Common Core: High School - Statistics and Probability : High School: Statistics & Probability

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Example Question #261 : High School: Statistics & Probability

A group of market analysts take the inventory of a company's production of a specific sports car. The cars produced by the company vary in both color and engine size: six cylinders (i.e. V6) or eight cylinders (i.e. V8). The data is contained in the provided table.

Given that a car is jade green, what is the probability that it has a V6?

Possible Answers:

Correct answer:

Explanation:

In order to solve this problem, we need to discuss probabilities and more specifically conditional probabilities. We will start with discussing probabilities in a general sense. A probability is generally defined as the chances or likelihood of an event occurring. It is calculated by identifying two components: the event and the sample space. The event is defined as the favorable outcome or success that we wish to observe. On the other hand, the sample space is defined as the set of all possible outcomes for the event. Mathematically we calculate probabilities by dividing the event by the sample space:

Let's use a simple example: the rolling of a die. We want to know the probability of rolling a one. We know that the sample space is six because there are six sides or outcomes to the die. Also, we know that there is only a single side with a value of one; therefore,

Now, let's convert this into a percentage:

Probabilities expressed in fraction form will have values between zero and one. One indicates that an event will definitely occur, while zero indicates that an event will not occur. Likewise, probabilities expressed as percentages possess values between zero and one hundred percent where probabilities closer to zero are unlikely to occur and those close to one hundred percent are more likely to occur. 

Now that we understand the definition of a probability in its most general sense, we can investigate conditional probabilities. A conditional probability is defined as the probability that event B will occur given the information that an event A has already occurred. It is expressed using the following equation:

In this equation, the probability of event B given that event A has occurred is equal to the probability of the intersection of events A and B divided by the probability of event A. Before we get into the specifics of answering this particular question, we should look at an example of conditional probability. Let's observe a dice rolling example. Suppose a person is rolling two fair dice, given that the first die equals four what is the probability that the roll's total will be less than or equal to seven. First, lets set up the equation:

 

Now, let's calculate the probability of rolling a four. We will do this by creating a matrix of possible outcomes. In this table, the possible values of the first die are written in the first row, while the possible values of the second die are written in the first column. 

Screen shot 2016 03 10 at 9.48.23 am

When we look at this graph, we can see that there are six possibilities of rolling a four in this scenario (they are highlighted in red in the following figure).

Screen shot 2016 03 10 at 10.31.37 am

There are thirty-six total outcomes; therefore, the probability of rolling a four on the first die can be written as follows:

Next, we need to calculate the intersection of the probabilities of rolling a four on the first die and rolling a total less than or equal to seven. Let's start by finding out the probability of rolling a seven or less with two fair dice.

Screen shot 2016 03 10 at 10.50.46 am

Twenty-one out of thirty-six possibilities result in a total roll value less than or equal to seven. Now, we can see where these values intersect with the probability of die one being a four.

Screen shot 2016 03 10 at 12.21.46 pm

In this table, we can see that that there are three possibilities where these two probabilities intersect; therefore, we can denote their intersection in the following manner:

Last, let's use substitution to solve our conditional probability.

Reduce.

It is important to note that if the events are independent, then the probability of event B given event A is simply the probability of event B because event A does not affect it.

We can now use this information to answer this particular question. This question asks us to calculate the probability that a car has a V6 engine given that it is jade green in color. Let's start by constructing the conditional probability equation.

Let's use the given table to find the probability of the intersection of a car being jade green with a V6 engine.

Now, let's find the probability that a car will be jade green.

We have enough information to use substitution and solve for the conditional probability.

Simplify and solve.

Example Question #262 : High School: Statistics & Probability

A group of market analysts take the inventory of a company's production of a specific sports car. The cars produced by the company vary in both color and engine size: six cylinders (i.e. V6) or eight cylinders (i.e. V8). The data is contained in the provided table.

Given that a car is jade green, what is the probability that it has a V6?

Possible Answers:

Correct answer:

Explanation:

In order to solve this problem, we need to discuss probabilities and more specifically conditional probabilities. We will start with discussing probabilities in a general sense. A probability is generally defined as the chances or likelihood of an event occurring. It is calculated by identifying two components: the event and the sample space. The event is defined as the favorable outcome or success that we wish to observe. On the other hand, the sample space is defined as the set of all possible outcomes for the event. Mathematically we calculate probabilities by dividing the event by the sample space:

Let's use a simple example: the rolling of a die. We want to know the probability of rolling a one. We know that the sample space is six because there are six sides or outcomes to the die. Also, we know that there is only a single side with a value of one; therefore,

Now, let's convert this into a percentage:

Probabilities expressed in fraction form will have values between zero and one. One indicates that an event will definitely occur, while zero indicates that an event will not occur. Likewise, probabilities expressed as percentages possess values between zero and one hundred percent where probabilities closer to zero are unlikely to occur and those close to one hundred percent are more likely to occur. 

Now that we understand the definition of a probability in its most general sense, we can investigate conditional probabilities. A conditional probability is defined as the probability that event B will occur given the information that an event A has already occurred. It is expressed using the following equation:

In this equation, the probability of event B given that event A has occurred is equal to the probability of the intersection of events A and B divided by the probability of event A. Before we get into the specifics of answering this particular question, we should look at an example of conditional probability. Let's observe a dice rolling example. Suppose a person is rolling two fair dice, given that the first die equals four what is the probability that the roll's total will be less than or equal to seven. First, lets set up the equation:

 

Now, let's calculate the probability of rolling a four. We will do this by creating a matrix of possible outcomes. In this table, the possible values of the first die are written in the first row, while the possible values of the second die are written in the first column. 

Screen shot 2016 03 10 at 9.48.23 am

When we look at this graph, we can see that there are six possibilities of rolling a four in this scenario (they are highlighted in red in the following figure).

Screen shot 2016 03 10 at 10.31.37 am

There are thirty-six total outcomes; therefore, the probability of rolling a four on the first die can be written as follows:

Next, we need to calculate the intersection of the probabilities of rolling a four on the first die and rolling a total less than or equal to seven. Let's start by finding out the probability of rolling a seven or less with two fair dice.

Screen shot 2016 03 10 at 10.50.46 am

Twenty-one out of thirty-six possibilities result in a total roll value less than or equal to seven. Now, we can see where these values intersect with the probability of die one being a four.

Screen shot 2016 03 10 at 12.21.46 pm

In this table, we can see that that there are three possibilities where these two probabilities intersect; therefore, we can denote their intersection in the following manner:

Last, let's use substitution to solve our conditional probability.

Reduce.

It is important to note that if the events are independent, then the probability of event B given event A is simply the probability of event B because event A does not affect it.

We can now use this information to answer this particular question. This question asks us to calculate the probability that a car has a V6 engine given that it is jade green in color. Let's start by constructing the conditional probability equation.

Let's use the given table to find the probability of the intersection of a car being jade green with a V6 engine.

Now, let's find the probability that a car will be jade green.

We have enough information to use substitution and solve for the conditional probability.

Simplify and solve.

Example Question #263 : High School: Statistics & Probability

A group of market analysts take the inventory of a company's production of a specific sports car. The cars produced by the company vary in both color and engine size: six cylinders (i.e. V6) or eight cylinders (i.e. V8). The data is contained in the provided table.

Given that a car is jade green, what is the probability that it has a V6?

Possible Answers:

Correct answer:

Explanation:

In order to solve this problem, we need to discuss probabilities and more specifically conditional probabilities. We will start with discussing probabilities in a general sense. A probability is generally defined as the chances or likelihood of an event occurring. It is calculated by identifying two components: the event and the sample space. The event is defined as the favorable outcome or success that we wish to observe. On the other hand, the sample space is defined as the set of all possible outcomes for the event. Mathematically we calculate probabilities by dividing the event by the sample space:

Let's use a simple example: the rolling of a die. We want to know the probability of rolling a one. We know that the sample space is six because there are six sides or outcomes to the die. Also, we know that there is only a single side with a value of one; therefore,

Now, let's convert this into a percentage:

Probabilities expressed in fraction form will have values between zero and one. One indicates that an event will definitely occur, while zero indicates that an event will not occur. Likewise, probabilities expressed as percentages possess values between zero and one hundred percent where probabilities closer to zero are unlikely to occur and those close to one hundred percent are more likely to occur. 

Now that we understand the definition of a probability in its most general sense, we can investigate conditional probabilities. A conditional probability is defined as the probability that event B will occur given the information that an event A has already occurred. It is expressed using the following equation:

In this equation, the probability of event B given that event A has occurred is equal to the probability of the intersection of events A and B divided by the probability of event A. Before we get into the specifics of answering this particular question, we should look at an example of conditional probability. Let's observe a dice rolling example. Suppose a person is rolling two fair dice, given that the first die equals four what is the probability that the roll's total will be less than or equal to seven. First, lets set up the equation:

 

Now, let's calculate the probability of rolling a four. We will do this by creating a matrix of possible outcomes. In this table, the possible values of the first die are written in the first row, while the possible values of the second die are written in the first column. 

Screen shot 2016 03 10 at 9.48.23 am

When we look at this graph, we can see that there are six possibilities of rolling a four in this scenario (they are highlighted in red in the following figure).

Screen shot 2016 03 10 at 10.31.37 am

There are thirty-six total outcomes; therefore, the probability of rolling a four on the first die can be written as follows:

Next, we need to calculate the intersection of the probabilities of rolling a four on the first die and rolling a total less than or equal to seven. Let's start by finding out the probability of rolling a seven or less with two fair dice.

Screen shot 2016 03 10 at 10.50.46 am

Twenty-one out of thirty-six possibilities result in a total roll value less than or equal to seven. Now, we can see where these values intersect with the probability of die one being a four.

Screen shot 2016 03 10 at 12.21.46 pm

In this table, we can see that that there are three possibilities where these two probabilities intersect; therefore, we can denote their intersection in the following manner:

Last, let's use substitution to solve our conditional probability.

Reduce.

It is important to note that if the events are independent, then the probability of event B given event A is simply the probability of event B because event A does not affect it.

We can now use this information to answer this particular question. This question asks us to calculate the probability that a car has a V6 engine given that it is jade green in color. Let's start by constructing the conditional probability equation.

Let's use the given table to find the probability of the intersection of a car being jade green with a V6 engine.

Now, let's find the probability that a car will be jade green.

We have enough information to use substitution and solve for the conditional probability.

Simplify and solve.

Example Question #264 : High School: Statistics & Probability

A group of market analysts take the inventory of a company's production of a specific sports car. The cars produced by the company vary in both color and engine size: six cylinders (i.e. V6) or eight cylinders (i.e. V8). The data is contained in the provided table.

Given that a car is jade green, what is the probability that it has a V6?

Possible Answers:

Correct answer:

Explanation:

In order to solve this problem, we need to discuss probabilities and more specifically conditional probabilities. We will start with discussing probabilities in a general sense. A probability is generally defined as the chances or likelihood of an event occurring. It is calculated by identifying two components: the event and the sample space. The event is defined as the favorable outcome or success that we wish to observe. On the other hand, the sample space is defined as the set of all possible outcomes for the event. Mathematically we calculate probabilities by dividing the event by the sample space:

Let's use a simple example: the rolling of a die. We want to know the probability of rolling a one. We know that the sample space is six because there are six sides or outcomes to the die. Also, we know that there is only a single side with a value of one; therefore,

Now, let's convert this into a percentage:

Probabilities expressed in fraction form will have values between zero and one. One indicates that an event will definitely occur, while zero indicates that an event will not occur. Likewise, probabilities expressed as percentages possess values between zero and one hundred percent where probabilities closer to zero are unlikely to occur and those close to one hundred percent are more likely to occur. 

Now that we understand the definition of a probability in its most general sense, we can investigate conditional probabilities. A conditional probability is defined as the probability that event B will occur given the information that an event A has already occurred. It is expressed using the following equation:

In this equation, the probability of event B given that event A has occurred is equal to the probability of the intersection of events A and B divided by the probability of event A. Before we get into the specifics of answering this particular question, we should look at an example of conditional probability. Let's observe a dice rolling example. Suppose a person is rolling two fair dice, given that the first die equals four what is the probability that the roll's total will be less than or equal to seven. First, lets set up the equation:

 

Now, let's calculate the probability of rolling a four. We will do this by creating a matrix of possible outcomes. In this table, the possible values of the first die are written in the first row, while the possible values of the second die are written in the first column. 

Screen shot 2016 03 10 at 9.48.23 am

When we look at this graph, we can see that there are six possibilities of rolling a four in this scenario (they are highlighted in red in the following figure).

Screen shot 2016 03 10 at 10.31.37 am

There are thirty-six total outcomes; therefore, the probability of rolling a four on the first die can be written as follows:

Next, we need to calculate the intersection of the probabilities of rolling a four on the first die and rolling a total less than or equal to seven. Let's start by finding out the probability of rolling a seven or less with two fair dice.

Screen shot 2016 03 10 at 10.50.46 am

Twenty-one out of thirty-six possibilities result in a total roll value less than or equal to seven. Now, we can see where these values intersect with the probability of die one being a four.

Screen shot 2016 03 10 at 12.21.46 pm

In this table, we can see that that there are three possibilities where these two probabilities intersect; therefore, we can denote their intersection in the following manner:

Last, let's use substitution to solve our conditional probability.

Reduce.

It is important to note that if the events are independent, then the probability of event B given event A is simply the probability of event B because event A does not affect it.

We can now use this information to answer this particular question. This question asks us to calculate the probability that a car has a V6 engine given that it is jade green in color. Let's start by constructing the conditional probability equation.

Let's use the given table to find the probability of the intersection of a car being jade green with a V6 engine.

Now, let's find the probability that a car will be jade green.

We have enough information to use substitution and solve for the conditional probability.

Simplify and solve.

Example Question #265 : High School: Statistics & Probability

A group of market analysts take the inventory of a company's production of a specific sports car. The cars produced by the company vary in both color and engine size: six cylinders (i.e. V6) or eight cylinders (i.e. V8). The data is contained in the provided table.

Given that a car is jade green, what is the probability that it has a V6?

Possible Answers:

Correct answer:

Explanation:

In order to solve this problem, we need to discuss probabilities and more specifically conditional probabilities. We will start with discussing probabilities in a general sense. A probability is generally defined as the chances or likelihood of an event occurring. It is calculated by identifying two components: the event and the sample space. The event is defined as the favorable outcome or success that we wish to observe. On the other hand, the sample space is defined as the set of all possible outcomes for the event. Mathematically we calculate probabilities by dividing the event by the sample space:

Let's use a simple example: the rolling of a die. We want to know the probability of rolling a one. We know that the sample space is six because there are six sides or outcomes to the die. Also, we know that there is only a single side with a value of one; therefore,

Now, let's convert this into a percentage:

Probabilities expressed in fraction form will have values between zero and one. One indicates that an event will definitely occur, while zero indicates that an event will not occur. Likewise, probabilities expressed as percentages possess values between zero and one hundred percent where probabilities closer to zero are unlikely to occur and those close to one hundred percent are more likely to occur. 

Now that we understand the definition of a probability in its most general sense, we can investigate conditional probabilities. A conditional probability is defined as the probability that event B will occur given the information that an event A has already occurred. It is expressed using the following equation:

In this equation, the probability of event B given that event A has occurred is equal to the probability of the intersection of events A and B divided by the probability of event A. Before we get into the specifics of answering this particular question, we should look at an example of conditional probability. Let's observe a dice rolling example. Suppose a person is rolling two fair dice, given that the first die equals four what is the probability that the roll's total will be less than or equal to seven. First, lets set up the equation:

 

Now, let's calculate the probability of rolling a four. We will do this by creating a matrix of possible outcomes. In this table, the possible values of the first die are written in the first row, while the possible values of the second die are written in the first column. 

Screen shot 2016 03 10 at 9.48.23 am

When we look at this graph, we can see that there are six possibilities of rolling a four in this scenario (they are highlighted in red in the following figure).

Screen shot 2016 03 10 at 10.31.37 am

There are thirty-six total outcomes; therefore, the probability of rolling a four on the first die can be written as follows:

Next, we need to calculate the intersection of the probabilities of rolling a four on the first die and rolling a total less than or equal to seven. Let's start by finding out the probability of rolling a seven or less with two fair dice.

Screen shot 2016 03 10 at 10.50.46 am

Twenty-one out of thirty-six possibilities result in a total roll value less than or equal to seven. Now, we can see where these values intersect with the probability of die one being a four.

Screen shot 2016 03 10 at 12.21.46 pm

In this table, we can see that that there are three possibilities where these two probabilities intersect; therefore, we can denote their intersection in the following manner:

Last, let's use substitution to solve our conditional probability.

Reduce.

It is important to note that if the events are independent, then the probability of event B given event A is simply the probability of event B because event A does not affect it.

We can now use this information to answer this particular question. This question asks us to calculate the probability that a car has a V6 engine given that it is jade green in color. Let's start by constructing the conditional probability equation.

Let's use the given table to find the probability of the intersection of a car being jade green with a V6 engine.

Now, let's find the probability that a car will be jade green.

We have enough information to use substitution and solve for the conditional probability.

Simplify and solve.

Example Question #266 : High School: Statistics & Probability

A group of market analysts take the inventory of a company's production of a specific sports car. The cars produced by the company vary in both color and engine size: six cylinders (i.e. V6) or eight cylinders (i.e. V8). The data is contained in the provided table.

Given that a car is jade green, what is the probability that it has a V6?

Possible Answers:

Correct answer:

Explanation:

In order to solve this problem, we need to discuss probabilities and more specifically conditional probabilities. We will start with discussing probabilities in a general sense. A probability is generally defined as the chances or likelihood of an event occurring. It is calculated by identifying two components: the event and the sample space. The event is defined as the favorable outcome or success that we wish to observe. On the other hand, the sample space is defined as the set of all possible outcomes for the event. Mathematically we calculate probabilities by dividing the event by the sample space:

Let's use a simple example: the rolling of a die. We want to know the probability of rolling a one. We know that the sample space is six because there are six sides or outcomes to the die. Also, we know that there is only a single side with a value of one; therefore,

Now, let's convert this into a percentage:

Probabilities expressed in fraction form will have values between zero and one. One indicates that an event will definitely occur, while zero indicates that an event will not occur. Likewise, probabilities expressed as percentages possess values between zero and one hundred percent where probabilities closer to zero are unlikely to occur and those close to one hundred percent are more likely to occur. 

Now that we understand the definition of a probability in its most general sense, we can investigate conditional probabilities. A conditional probability is defined as the probability that event B will occur given the information that an event A has already occurred. It is expressed using the following equation:

In this equation, the probability of event B given that event A has occurred is equal to the probability of the intersection of events A and B divided by the probability of event A. Before we get into the specifics of answering this particular question, we should look at an example of conditional probability. Let's observe a dice rolling example. Suppose a person is rolling two fair dice, given that the first die equals four what is the probability that the roll's total will be less than or equal to seven. First, lets set up the equation:

 

Now, let's calculate the probability of rolling a four. We will do this by creating a matrix of possible outcomes. In this table, the possible values of the first die are written in the first row, while the possible values of the second die are written in the first column. 

Screen shot 2016 03 10 at 9.48.23 am

When we look at this graph, we can see that there are six possibilities of rolling a four in this scenario (they are highlighted in red in the following figure).

Screen shot 2016 03 10 at 10.31.37 am

There are thirty-six total outcomes; therefore, the probability of rolling a four on the first die can be written as follows:

Next, we need to calculate the intersection of the probabilities of rolling a four on the first die and rolling a total less than or equal to seven. Let's start by finding out the probability of rolling a seven or less with two fair dice.

Screen shot 2016 03 10 at 10.50.46 am

Twenty-one out of thirty-six possibilities result in a total roll value less than or equal to seven. Now, we can see where these values intersect with the probability of die one being a four.

Screen shot 2016 03 10 at 12.21.46 pm

In this table, we can see that that there are three possibilities where these two probabilities intersect; therefore, we can denote their intersection in the following manner:

Last, let's use substitution to solve our conditional probability.

Reduce.

It is important to note that if the events are independent, then the probability of event B given event A is simply the probability of event B because event A does not affect it.

We can now use this information to answer this particular question. This question asks us to calculate the probability that a car has a V6 engine given that it is jade green in color. Let's start by constructing the conditional probability equation.

Let's use the given table to find the probability of the intersection of a car being jade green with a V6 engine.

Now, let's find the probability that a car will be jade green.

We have enough information to use substitution and solve for the conditional probability.

Simplify and solve.

Example Question #11 : Understand Conditional Probability And Interpreting Independence: Ccss.Math.Content.Hss Cp.A.3

A group of market analysts take the inventory of a company's production of a specific sports car. The cars produced by the company vary in both color and engine size: six cylinders (i.e. V6) or eight cylinders (i.e. V8). The data is contained in the provided table.

Given that a car is jade green, what is the probability that it has a V6?

Possible Answers:

Correct answer:

Explanation:

In order to solve this problem, we need to discuss probabilities and more specifically conditional probabilities. We will start with discussing probabilities in a general sense. A probability is generally defined as the chances or likelihood of an event occurring. It is calculated by identifying two components: the event and the sample space. The event is defined as the favorable outcome or success that we wish to observe. On the other hand, the sample space is defined as the set of all possible outcomes for the event. Mathematically we calculate probabilities by dividing the event by the sample space:

Let's use a simple example: the rolling of a die. We want to know the probability of rolling a one. We know that the sample space is six because there are six sides or outcomes to the die. Also, we know that there is only a single side with a value of one; therefore,

Now, let's convert this into a percentage:

Probabilities expressed in fraction form will have values between zero and one. One indicates that an event will definitely occur, while zero indicates that an event will not occur. Likewise, probabilities expressed as percentages possess values between zero and one hundred percent where probabilities closer to zero are unlikely to occur and those close to one hundred percent are more likely to occur. 

Now that we understand the definition of a probability in its most general sense, we can investigate conditional probabilities. A conditional probability is defined as the probability that event B will occur given the information that an event A has already occurred. It is expressed using the following equation:

In this equation, the probability of event B given that event A has occurred is equal to the probability of the intersection of events A and B divided by the probability of event A. Before we get into the specifics of answering this particular question, we should look at an example of conditional probability. Let's observe a dice rolling example. Suppose a person is rolling two fair dice, given that the first die equals four what is the probability that the roll's total will be less than or equal to seven. First, lets set up the equation:

 

Now, let's calculate the probability of rolling a four. We will do this by creating a matrix of possible outcomes. In this table, the possible values of the first die are written in the first row, while the possible values of the second die are written in the first column. 

Screen shot 2016 03 10 at 9.48.23 am

When we look at this graph, we can see that there are six possibilities of rolling a four in this scenario (they are highlighted in red in the following figure).

Screen shot 2016 03 10 at 10.31.37 am

There are thirty-six total outcomes; therefore, the probability of rolling a four on the first die can be written as follows:

Next, we need to calculate the intersection of the probabilities of rolling a four on the first die and rolling a total less than or equal to seven. Let's start by finding out the probability of rolling a seven or less with two fair dice.

Screen shot 2016 03 10 at 10.50.46 am

Twenty-one out of thirty-six possibilities result in a total roll value less than or equal to seven. Now, we can see where these values intersect with the probability of die one being a four.

Screen shot 2016 03 10 at 12.21.46 pm

In this table, we can see that that there are three possibilities where these two probabilities intersect; therefore, we can denote their intersection in the following manner:

Last, let's use substitution to solve our conditional probability.

Reduce.

It is important to note that if the events are independent, then the probability of event B given event A is simply the probability of event B because event A does not affect it.

We can now use this information to answer this particular question. This question asks us to calculate the probability that a car has a V6 engine given that it is jade green in color. Let's start by constructing the conditional probability equation.

Let's use the given table to find the probability of the intersection of a car being jade green with a V6 engine.

Now, let's find the probability that a car will be jade green.

We have enough information to use substitution and solve for the conditional probability.

Simplify and solve.

Example Question #11 : Understand Conditional Probability And Interpreting Independence: Ccss.Math.Content.Hss Cp.A.3

A group of market analysts take the inventory of a company's production of a specific sports car. The cars produced by the company vary in both color and engine size: six cylinders (i.e. V6) or eight cylinders (i.e. V8). The data is contained in the provided table.

Given that a car is jade green, what is the probability that it has a V6?

Possible Answers:

Correct answer:

Explanation:

In order to solve this problem, we need to discuss probabilities and more specifically conditional probabilities. We will start with discussing probabilities in a general sense. A probability is generally defined as the chances or likelihood of an event occurring. It is calculated by identifying two components: the event and the sample space. The event is defined as the favorable outcome or success that we wish to observe. On the other hand, the sample space is defined as the set of all possible outcomes for the event. Mathematically we calculate probabilities by dividing the event by the sample space:

Let's use a simple example: the rolling of a die. We want to know the probability of rolling a one. We know that the sample space is six because there are six sides or outcomes to the die. Also, we know that there is only a single side with a value of one; therefore,

Now, let's convert this into a percentage:

Probabilities expressed in fraction form will have values between zero and one. One indicates that an event will definitely occur, while zero indicates that an event will not occur. Likewise, probabilities expressed as percentages possess values between zero and one hundred percent where probabilities closer to zero are unlikely to occur and those close to one hundred percent are more likely to occur. 

Now that we understand the definition of a probability in its most general sense, we can investigate conditional probabilities. A conditional probability is defined as the probability that event B will occur given the information that an event A has already occurred. It is expressed using the following equation:

In this equation, the probability of event B given that event A has occurred is equal to the probability of the intersection of events A and B divided by the probability of event A. Before we get into the specifics of answering this particular question, we should look at an example of conditional probability. Let's observe a dice rolling example. Suppose a person is rolling two fair dice, given that the first die equals four what is the probability that the roll's total will be less than or equal to seven. First, lets set up the equation:

 

Now, let's calculate the probability of rolling a four. We will do this by creating a matrix of possible outcomes. In this table, the possible values of the first die are written in the first row, while the possible values of the second die are written in the first column. 

Screen shot 2016 03 10 at 9.48.23 am

When we look at this graph, we can see that there are six possibilities of rolling a four in this scenario (they are highlighted in red in the following figure).

Screen shot 2016 03 10 at 10.31.37 am

There are thirty-six total outcomes; therefore, the probability of rolling a four on the first die can be written as follows:

Next, we need to calculate the intersection of the probabilities of rolling a four on the first die and rolling a total less than or equal to seven. Let's start by finding out the probability of rolling a seven or less with two fair dice.

Screen shot 2016 03 10 at 10.50.46 am

Twenty-one out of thirty-six possibilities result in a total roll value less than or equal to seven. Now, we can see where these values intersect with the probability of die one being a four.

Screen shot 2016 03 10 at 12.21.46 pm

In this table, we can see that that there are three possibilities where these two probabilities intersect; therefore, we can denote their intersection in the following manner:

Last, let's use substitution to solve our conditional probability.

Reduce.

It is important to note that if the events are independent, then the probability of event B given event A is simply the probability of event B because event A does not affect it.

We can now use this information to answer this particular question. This question asks us to calculate the probability that a car has a V6 engine given that it is jade green in color. Let's start by constructing the conditional probability equation.

Let's use the given table to find the probability of the intersection of a car being jade green with a V6 engine.

Now, let's find the probability that a car will be jade green.

We have enough information to use substitution and solve for the conditional probability.

Simplify and solve.

Example Question #1 : Two Way Frequency Tables: Ccss.Math.Content.Hss Cp.A.4

A high school wants to assess the science elective courses that its students have chosen for their next year of education. Thirty-three freshmen, ten sophomores, eight juniors, and twenty-two seniors chose to take astronomy. Eighteen freshmen, twenty-four sophomores, thirty-three juniors, and twenty seniors are planning to take ecology. Twelve freshmen, thirty-eight sophomores, eighteen juniors, and twenty-five seniors want to take physics. Last, four freshmen, fourteen sophomores, fifteen juniors, and twenty-eight seniors chose to take chemistry. 

Use this information to create a two-way frequency table and calculate the probability that a senior will take astronomy.

Possible Answers:

Cannot be determined

Correct answer:

Explanation:

In order to solve this problem, we need to discuss probabilities and frequency charts. A probability is generally defined as the chances or likelihood of an event occurring. It is calculated by identifying two components: the event and the sample space. The event is defined as the favorable outcome or success that we wish to observe. On the other hand, the sample space is defined as the set of all possible outcomes for the event. Mathematically we calculate probabilities by dividing the event by the sample space:

Let's use a simple example: the rolling of a die. We want to know the probability of rolling a one. We know that the sample space is six because there are six sides or outcomes to the die. Also, we know that there is only a single side with a value of one; therefore,

Now, let's convert this into a percentage:

Probabilities expressed in fraction form will have values between zero and one. One indicates that an event will definitely occur, while zero indicates that an event will not occur. Likewise, probabilities expressed as percentages possess values between zero and one hundred percent where probabilities closer to zero are unlikely to occur and those close to one hundred percent are more likely to occur. 

Now, we will start by constructing a table. The question presents data associated with two different types of variables: grade level and class. There are four grade levels (i.e. freshman, sophomores, juniors, and seniors) and four elective science classes (i.e. astronomy, ecology, physics, and chemistry). We need to make a table that has four rows and four columns. Next, we can input the data contained in the table. Last we will add up each row and column in order to gain totals for each variable. If you have done this properly, then you should have created a table similar to the following:

Screen shot 2016 03 23 at 5.54.52 pm

After, the two-way table has been constructed you can then use it to solve the question: what is the probability that a senior will take astronomy? 

First, we need to create the following ratio: number seniors planning to take the astrology class to the total number of seniors.

Substitute values using the table and solve.

Example Question #261 : High School: Statistics & Probability

A high school wants to assess the science elective courses that its students have chosen for their next year of education. Thirty-three freshmen, ten sophomores, eight juniors, and twenty-two seniors chose to take astronomy. Eighteen freshmen, twenty-four sophomores, thirty-three juniors, and twenty seniors are planning to take ecology. Twelve freshmen, thirty-eight sophomores, eighteen juniors, and twenty-five seniors want to take physics. Last, four freshmen, fourteen sophomores, fifteen juniors, and twenty-eight seniors chose to take chemistry. 

Use this information to create a two-way frequency table and calculate the probability that a senior will take astronomy.

Possible Answers:

Cannot be determined

Correct answer:

Explanation:

In order to solve this problem, we need to discuss probabilities. A probability is generally defined as the chances or likelihood of an event occurring. It is calculated by identifying two components: the event and the sample space. The event is defined as the favorable outcome or success that we wish to observe. On the other hand, the sample space is defined as the set of all possible outcomes for the event. Mathematically we calculate probabilities by dividing the event by the sample space:

Let's use a simple example: the rolling of a die. We want to know the probability of rolling a one. We know that the sample space is six because there are six sides or outcomes to the die. Also, we know that there is only a single side with a value of one; therefore,

Now, let's convert this into a percentage:

Probabilities expressed in fraction form will have values between zero and one. One indicates that an event will definitely occur, while zero indicates that an event will not occur. Likewise, probabilities expressed as percentages possess values between zero and one hundred percent where probabilities closer to zero are unlikely to occur and those close to one hundred percent are more likely to occur. 

Now, we will start by constructing a table. The question presents data associated with two different types of variables: grade level and class. There are four grade levels (i.e. freshman, sophomores, juniors, and seniors) and four elective science classes (i.e. astronomy, ecology, physics, and chemistry). We need to make a table that has four rows and four columns. Next, we can input the data contained in the table. Last we will add up each row and column in order to gain totals for each variable. If you have done this properly, then you should have created a table similar to the following:

Screen shot 2016 03 23 at 5.54.52 pm

After, the two-way table has been constructed you can then use it to solve the question: what is the probability that a senior will take astronomy? 

First we need to create the following ratio: number seniors planning to take the astrology class to the total number of seniors.

Substitute values using the table and solve.

All Common Core: High School - Statistics and Probability Resources

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