Interpreting Data: What's the Mean?

Lesson Plan - Get It!

Audio:

• What do you think of when you hear the term mean?
• Do you see someone making fun of another person?
• What about two people getting into a fight?

Typically, we associate the word mean with someone being unkind to another person, but in math, the term mean has nothing to do with feelings or the way people are treated. In math, the mean is a way of collecting data.

To find the mean in math is the same as finding the average. Finding the mean, or average, is easy, but can take a little time and patience. Let's get back to the example of Josie and the soccer team.

Josie's soccer team scored the following number of goals at their games this season:

You know how many goals Josie's team scored at each game, but you want to know how many goals they scored on average per game. You need to find the mean in order to determine that answer.

To find the mean, you start by adding all of the goals scored to find the total:

2 + 5 + 2 + 3 + 3 = 15

When you add all the numbers together, you find that Josie's team scored a total of 15 goals this season. However, 15 is not the mean! You still have one more step to complete.

Divide the sum by the number of pieces of data with which you are working; in this case, it's the number of games they played. Josie's team played five games, meaning you had five pieces of data that you added together.

Divide 15 by 5 to find the mean, or average:

15 ÷ 5 = 3

Josie's team scored an average of 3 goals per game. 3 is the mean!

Finding the mean is easy and fun! Move on to the next section so you can practice finding the mean.