1. Warm Up Problem
Solve each problem.

2. Mean Absolute Deviation
Lesson 11-4

3. Objectives
I can find and define mean absolute deviation.

4. Vocabulary
mean absolute deviation – the average distance between each data value and the mean

5. Example 1
The table shows the maximum speeds of eight roller coasters. Find the mean absolute deviation of the set of data. Describe what the mean absolute deviation represents.

6. Example 1

7. Example 1
The mean absolute deviation is This means that the average distance each value is from the mean is 12.5 miles per hour.

8. In Summary…
1. Add 2. Divide 3. Subtract 4. Add 5. Divide

9. Got It?
1. The table shows speeds of ten birds. Find the mean absolute deviation of the data. Round to the nearest hundredth. Describe what the mean absolute deviation represents.

10. Example 2
The top five salaries and the bottom five salaries for the 2010 New York Yankees are shown in the table below. Salaries are in millions of dollars and are rounded to the nearest hundredth.
Find the mean absolute deviation for each set of data. Round to the nearest hundredth.
Find the mean of the top five salaries:
= 23.40

11. Example 2
The mean is about $23.4 million.
Find the mean absolute deviation of the top five salaries:
Subtract the mean from each number and find mean.
= 4.19
The mean absolute deviation is $4.19 million.

12. Example 2
Find the mean of the bottom five salaries:
= 0.43
The mean is about $0.43 million.
Find the mean absolute deviation of the bottom five salaries:
= 0.01
The mean absolute deviation is about $0.01 million.

13. The set that has the closest data is the bottom salaries.
Example 2
b. Write a few sentences comparing their variation.
In other words, who had the higher mean?
Who had the higher mean absolute deviation?
Which set has data that is closer to each other?
The top salaries had the higher mean. The top salaries had the higher mean absolute deviation?
The set that has the closest data is the bottom salaries.

14. Got It?
2. The table shows the running time in minutes for two kinds of movies. Find the mean absolute deviation for each set of data. Round to the nearest hundredth. Then write a few sentences comparing their variation.