The mean is the sum of all the numbers divided by the total amount of numbers in the data set.  It is also the average.

Add the numbers.

There are nine numbers provided.

Divide the sum with nine.

The mean is:  

The best way to solve this is to first determine what her final total score should be. If she needs an average of , with a total of  tests, she must achieve a total score of  (which is ). Then, to determine what score she must achieve on the final test, we simply subtract her previous scores. . So her final score must be at least  if she is going to achieve her goal.

To find the average, we simply add all of the scores together and divide by the number of tests (in this case ). We find a sum of , and when we divide by 5, we find a final average score of .

Add up all of the values in the data set and divide the sum by the number of values of the set.

Find the mean of the following data set:

Whenever we are working with a data set, it can be helpful to put the terms in order:

Now that our terms are in order, we can do all sorts of things with them.

In this case, we need to find the mean. This is essentially the same as the average. 

Begin by finding the sum of our terms.

Now, because we have ten terms, we need to divide by 10

Luckily, we are provided with a data set that is already in numerical order: 

.

To find the range, we subtract the lowest value from the highest, 

.

To find the mean, we add all of the data pieces and divide by the number of data pieces, 

.

To find the mode, we search for numbers tha appear more than once. Since none of these data values appear more than once, we have no mode. 

The course grade average is calculated by using Sally's three test scores and final exam. student must score at least an average of ; therefore we can write the following:

Given that the average is calculated using three test scores and a final weighted as two regular tests, we can write the following equation. 

Let's use these equations to construct an inequality where we will substitute in our known values and let a variable, , equal the final score needed to earn an a  or above.

Sally needs to at least score a  on the final to score  or above.

In order to find out how much money Alex earned during the fourth hour, we need to understand how to find the mean of a set of numbers (also known as the 'average'). To find the mean of any set of numbers, we first add together all of the numbers in the set to find a total sum, and then we divide this sum by the amount of numbers that are in the set:

Let's look at the information given to us in this problem. We know several things:

- The mean amount of money that Alex earned each hour was 

- Alex worked for a total of 

- The amount of money earned for three out of four of the hours (; ; )

We DON'T know how much money Alex earned during the 4th hour, but we can figure it out by plugging in what we know into the equation for finding the mean of a set, as follows:

For "Mean", we plug in the mean amount that Alex earned (which was ). For "sum of all numbers" we plug in the amount that Alex earned for every hour, and add them all together. Since we only know how much money Alex earned for three out of the four hours, we'll use  as a placeholder for the fourth hour. For "amount of numbers in set", we plug in , since that is the total number of hours that Alex worked.

Now, all we need to do is solve for . We'll do this by first adding together all of the numbers in the numerator of our fraction:

Next, we multiply both sides of our equation by , in order to get rid of our fraction:

Finally, subtract  from both side to get  by itself:

So,  is our answer. 

0, 1, one fourth, twenty five percent, , 16, 25

First we will list the numbers from least to greatest:

0, one fourth, twenty five percent, , 1, 16, 25

 The median is the middle number, or , which can also be expressed as