This section tests your ability to understand and think critically about information from tables, charts, and graphs. You will also be asked to find the mean, median, and mode of a set of numbers.
Here are some concepts that you may see on the test.
Mean is the fancy word for average. To find the mean, or average, of a set of numbers, there is a really simple set of steps to follow:
- Add all of the numbers together.
- Divide the sum of those numbers by the number of values in the set.
Let’s look at an example:
14, 88, 43, 25, 10, 33, 85, 26
14 + 88 + 43 + 25 + 10 + 33 + 85 + 26 = 324
324 ÷ 8 = 40.5
After adding all of the numbers together, we divide the sum by 8, because there are 8 numbers in the set. The mean, or average, of the data set is 40.5.
On the test, questions about the mean of numbers may be presented in word problems. Take a look at an example:
Kelly wants to know what her grade will be at the end of the year. Her grades are listed below. What will be her average?
89, 76, 100, 100, 92, 72, 83
Here are the steps to solving this problem:
89 + 76 + 100 + 100 + 92 + 72 + 83 = 612
612 ÷ 7 = 87.43
The median is the middle value in a set of numbers. To find the median of a set of numbers, follow these steps:
- Order the numbers from least to greatest.
- Find the number in the middle.
If you have a data set with an odd amount of numbers, finding the middle value is super easy; however, if you have a data set with an even amount of numbers, there will be two values in the middle. In this case, find the mean, or average, of those two numbers. That average is the median.
Let’s look at how this might appear on the test:
What is the median for the following set of numbers?
74, 39, 26, 89, 100, 24, 55, 87
First, we order the numbers from least to greatest. Then, we find the value in the middle. Since there are 8 numbers in this set, there are two values in the middle: 55 and 74. Find the mean, or average, of these numbers. The median is 64.5.
24, 26, 39, 55, 74, 87, 89, 100
55 + 74 = 129
129 ÷ 2 = 64.5
In a data set, the mode is the number or numbers that appear the most. Unlike the mean and median, the mode can have more than one answer. Look at an example:
Sally wants to know which bowling score she got the most often during the season. Find the mode.
117, 183, 173, 201, 117, 138, 129
In this data set, 117 appears twice, while the other numbers only appear once; therefore, 117 is the mode.