ISEE Middle Level Math : Data Analysis and Probability

Study concepts, example questions & explanations for ISEE Middle Level Math

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Example Questions

Example Question #341 : Data Analysis And Probability

If you got  on your first four tests, what must you get to at least have an average grade of ?  

Possible Answers:

Correct answer:

Explanation:

To find the average, you must add all of the grades together and divide by how many you have.  

Since you need to find a fifth grade to get a  average, your equation will be, 

.  

To work backwards to find , you must first multiple both sides by  resulting in,

 .  

Then you subtract all the other grades from your point total of  and you are left with .

Example Question #81 : Mean

Joshua scored 75, 85, 55, 95, 70, and 100 on his math tests.  What grade would James need to receive on his last test of the semester in order to recieve an average off 82% for all 7 tests?

Possible Answers:

Correct answer:

Explanation:

In order for James to receive an 82% as his average or mean score for the seven tests, he would need to recieve a 94% on his last test.  

To calculate what the total amount of points needed, first find out how many points in total he would need to have this average.  

 represents how many points in total he would need to have the 82 average.

If you add up all of the grades he received on the six tests that he already took, he has accumulated a total of 480 points. The difference between the amount of points he needs, which is 574 and the amount of points he needs is calculated as follows:

He would need to get a 94 on his last test in order to get an 82% average or mean for his 7 test grades.

Example Question #343 : Data Analysis And Probability

Use the following data set to answer the question.

Find the mean.

Possible Answers:

Correct answer:

Explanation:

To find the mean (or average) of a data set, you add all of the numbers within the set, then divide by how many numbers are in the data set.  In other words,

 

We will first find the sum.

 

Now, we will determine how many numbers are in the data set. 

This is true, because the set contains 5 numbers.  

 

Now, we will substitute. 

 

Therefore, the mean of the data set is .

Example Question #344 : Data Analysis And Probability

Find the mean of the following data set:

Possible Answers:

Correct answer:

Explanation:

Find the mean of the following data set:

To find the median, we need to add up all our terms and divide by the number of terms. This is the same process used to find the average of a group of numbers

Because there are 7 terms in our series, we divide by 7

So, we can say our answer is 61

Example Question #345 : Data Analysis And Probability

Use the following data set to answer the question.

Find the mean.

Possible Answers:

Correct answer:

Explanation:

To find the mean of a data set, we add all of the numbers within the set, then we divide that by the number of numbers within the set.  In other words, we will use this formula:

So, using the data set

we will first find the sum of the numbers.  This means we will add the numbers.  So,

 

Now, we will find the number of numbers.  This just means that we will count and see how many numbers are in the set.  So, in the set

we can see there are 7 numbers.  So,

 

Now, we can substitute into the formula.  We get

 

Therefore, the mean is .

Example Question #341 : Data Analysis And Probability

Find the mean in this set of numbers:

Possible Answers:

Correct answer:

Explanation:

To solve, first add all the numbers in the set:

Then divide by the amount of numbers in the set:

Answer: The mean is .

Example Question #341 : Data Analysis

What is the mean of the following data set?

Possible Answers:

Correct answer:

Explanation:

What is the mean of the following data set?

First, find the sum of our terms:

Next, divide the sum by the total number of terms

So our answer is 1010

Example Question #348 : Data Analysis And Probability

Use the following data set to answer the question.

Find the mean.

Possible Answers:

Correct answer:

Explanation:

To find the mean of a data set, we will use the following formula:

 

So, given the data set

we will first find the sum.  To find the sum, we will add the numbers together.  So,

 

Now, we will find the number of numbers within the set.  To do this, we will simply count and see how many numbers are in the set. So,

 

Now, we will use this and substitute into the formula.  We get

 

Therefore, the mean of the data set is .

Example Question #342 : Data Analysis And Probability

You have a test average for a class of  and your take another test on which you score a .  How does this affect your average?

Possible Answers:

Cannot determine

Stays the same

Increases

Decreases

Correct answer:

Increases

Explanation:

Since averages are outlier sensitive, they will go up when higher values are added or go down when lower numbers are added.  Since the new test grade is higher than the average, the average will increase. 

Example Question #653 : Isee Middle Level (Grades 7 8) Mathematics Achievement

Find the mean of the following data set:

Possible Answers:

Correct answer:

Explanation:

Find the mean of the following data set:

To find the mean, we need to add up all our terms and divide by the number of terms.

We have eleven terms, so do the following:

 

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