Stuck? Start here. Read the steps, try the problem, then check your answer.
I can…
I can determine the mean of a data set, use a target mean to find a missing value, and explain the mean as the fair share and the balance point of the data.
Key words
Mean — The average of a data set. Add all the values, then divide by how many values there are.
Average — Another word for the mean — the amount each value would be if the total were shared equally.
Measure of center — A single number used to describe the middle, or typical value, of a whole data set.
Balance point — The value where the total distance of the data above it equals the total distance below it. The mean is the balance point.
Data set — The whole collection of values that were gathered or measured.
Target mean — The mean a person is trying to reach.
Target total — The target mean times the number of values.
Steps
Miguel's 4 days of earnings are shown with counters. When I combine all of the counters, there are 60 of them, which means Miguel earned $60 in all.
Now I redistribute the 60 counters equally among the 4 days. Each of the 4 groups ends up with 15 counters.
The arithmetic does exactly the same thing: I find the total, 60, and divide it by the number of days, 4. So 60 ÷ 4 = 15.
We can use $15 to describe Miguel's typical daily earnings. That leveled value is the mean.
Try it
Leo read 9, 15, 11, and 17 pages on four nights. What is the mean number of pages he read each night?
Check your answer
13
Add the values: 9 + 15 + 11 + 17 = 52. There are 4 values, so the mean is 52 ÷ 4 = 13 pages.
Sentence starter
I know ___ because ___.
Goal: I can explain my reasoning using the words mean, average, measure of center, balance point, and data set.