Recall how to find the average of a set of numbers:

We can then set up the following equation. Let  be the score of the fifth test.

Solve for .

Joseph must score a  on his next test to pass the class.

The average distance Peter ran over five days is the sum of the distances he ran divided by five, so first, add the distances:

Rewrite the expressions in terms of halves, and add numerators:

Peter ran a total of six miles. Since we are asked for an answer in feet, first, multiply this by 5,280 feet per mile:

feet.

Now, divide by 5:

feet per day, the correct response.

To find the mean, you must first add up all of the numbers in the set, then divide the total by how many numbers you have.

Let's start by adding up all the whole set.

Not counting the total, we see that we have  numbers in our set. We will divide  by  in order to get the mean.

Our answer is .

To find the mean, we must add up all of the numbers in our set, then divide our total by how many numbers we have.

Let's first add up the set. Remember to include the negative when adding.

If we count all of our numbers, not including the total, we can see that we have  numbers. Now we shall divide  from .

Our answer is .

To find the mean, we must first add up all of the numbers in our set, then divide the total by the number of numbers in our set.

Let's first add up all of our numbers.

Not including the total, we can see that we have  numbers in our set. We will divide  by  in order to get the mean.

Our answer is .

In order to find the mean, we must first add up all of the numbers in the set, then divide the total number by how many numbers we have.

If you have a calculator, then adding these fractions should be easy. If you don't have a calculator, then we will add them up by hand.

Right now we can't add our fractions together, as they have no common denominator. We must convert all of these fractions to have the same denominator and then we can add them.

 is a number that can have , , and  in it, so we will use this number as our denominator. So we will multiply  by ,  with , and  with  in order to have  as the denominator. Make sure to multiply the numerator too!

Since we have  fractions, we will divide  by . This is the same as saying we are multiplying it by .

Our answer is 

The median of a set of numbers is the number that is in the middle of the set when the numbers are written in increasing order (from smallest to largest).

When a list of numbers includes an even quantity, like the list in this question, you need to find the mean (average) of the two numbers in the middle.

The steps to find the median of this number set are below:

1. Rewrite the list of numbers so that the numbers are written in increasing order

2. Identify the number(s) in the middle of the set

3. Since there are two numbers in the middle of the set, find the average of the two numbers

The median of a data set with an odd number of elements is the middle value when the set is arranged in ascending order; the middle value of this nine-element set is the fifth value, 5.

The mode of a data set is the most frequently occurring element. Here, only 5 appears multiple times, so it is the mode.

The mean of a data set is the sum of its elements divided by the number of elements, which here is 9:

The mean and the mode are equal, but the mean is different. The correct answer is "II and III only".

The median of a data set with an even number of elements is the mean of the two elements that are in the middle when the elements are arranged in ascending order, such as this one. The middle elements of this ten-element set are both 5, so this is the median.

The median of a data set with an odd number of elements is the element that is in the middle when the elements are arranged in ascending order. 

If 0 is added to the set, it becomes 

.

If 5 is added, it becomes

.

If 100 is added, it becomes

.

In all cases, the middle element is 5, so the median remains 5. The correct choice is "I, II, and III".

To find the median, first reorder the prices in ascending order:

$2,  $3, $4, $5, $6, $7, $8, $10, $10

The median is the middle number in a data set.

Here, the middle number in this set of nine prices is the 5th number, which is $6.

$2,  $3, $4, $5, $6, $7, $8, $10, $10