Algebra 1 : Statistics and Probability
Study concepts, example questions & explanations for Algebra 1
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Example Questions
Example Question #51 : Statistics And Probability
If the average of 
If the average of 
If the average of the 
This makes the sum of the other two numbers to be 
Then the average of those two numbers is 
Example Question #52 : Statistics And Probability
If the average of 
If the average of 
If the average of the 
This makes the sum of the other three numbers to be 
Example Question #51 : Statistics And Probability
What is the average angle of a square?
The total degree of a square is 
Since a square has four angles, we divide 
Example Question #52 : Statistics And Probability
If Joe took three exams and scored 
We need an average of 
That means the sum of his exams must be 
We know the sum of his three exams which is 
The difference is 
Example Question #53 : Statistics And Probability
What is the average of the first four prime numbers?
The first four prime numbers are 
The sum is 
Since there are four numbers, the average is 
Example Question #54 : Statistics And Probability
Find the mean of the following numbers (round to the nearest tenth).
Add every number together and divide by the total number of numbers in the set (9) to get the following.
Example Question #55 : Statistics And Probability
Find the mean of 
The mean is the average of a set of numbers. The mean is found by adding up all of the numbers in the set and then dividing by the size of the set. There are 
Example Question #56 : Statistics And Probability
The mean of a data set is the average value of all values in the set.
James is taking a class which has 5 exams over the semester. James has already taken 3 exams, and his scores are 78, 85, and 96. If James wants to average at least 80 across all 5 exams, what is the average score he must have for his final 2 exams?
Solving this question involves understanding how the equation for mean of a data set works. Let's look at the data set so far:
Since all the elements of this data set are the same (test scores), let's call the missing values t.
We know we want our final average to be an 80, so let's look at the basic equation for finding mean, with 80 in place of x:
At this point, simple algebra takes over:
Thus, James must score an average of 70.5 on each of his remaining tests to average an 80 for the semester. This could mean he scores a 70 and 71, or a 90 and a 51, or any combination of scores that averages to at least 70.5. (By the looks of it, James is in good shape!)
Example Question #55 : Statistics And Probability
The mean of a data set is the average value of all values in the set.
Annie is budgeting for the holidays, and is trying to figure out how much money se should set aside to buy gifts for her family.
Over the last five years, she has spent 
To find the average cost of gifts, we simply sum all of our data points, then divide by the total number of points. In this case, we have an 
Some people will want to rearrange the numbers from least to greatest, but this is not strictly necessary for calculating the mean.
So on average, Annie will need to save 
Example Question #57 : Statistics And Probability
Using the data above, find the mean.
To find the mean, or average, of a set of data simply find the sum of all of the data and divide the total by the amount of data pieces (n),
So for this set of data,
11 is our average. (note that unlike finding the median and mode, the mean is not necessarily a piece of data currently in the data set)
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