MADMean Absolute

Deviation

How can you describe how far apart the responses are from

the center in a data set?

In this lesson you will learn how to describe the

distribution of data by using the mean absolute deviation

MAD.

Let’s Review

The mean of a set of data is the average.

0 + 0 + 0 + 1 + 1 + 1 + 2 + 2 + 3 + 4 + 5 + 5 = 2424 ÷ 12 = 2

A Common Mistake

The mean and mean absolute deviation are often confused because they both

include the word, “mean.”

Mean Mean absolute deviation

Core Lesson

2 222

Find the mean absolute deviation.

1 111

33

00

2 2 2 1 1 1 0 0 1 2 3+ 3 18 18 ÷ 12 = 1.5

Core Lesson

Let’s TRY ONE!!!

Core Lesson

Find the mean absolute deviation.

How many different states have you visited?1, 2, 2, 3, 4, 5, 6, 7, 12, 18

Core Lesson

Find the mean absolute deviation.

How many different states have you visited?1, 2, 2, 3, 4, 5, 6, 7, 12, 18

Mean is 6. Find each number’s distance from 6

Core Lesson

Find the mean absolute deviation.

How many different states have you visited?1, 2, 2, 3, 4, 5, 6, 7, 12, 18

5 4 4 3 2 1 0 1 6 12

Core Lesson

Find the mean absolute deviation.

How many different states have you visited?1, 2, 2, 3, 4, 5, 6, 7, 12, 18

5 4 4 3 2 1 0 1 6 12

38 ÷ 10 = 3.8 MAD is 3.8

Core Lesson

Let’s TRY ANOTHER ONE!!!

Guided Practice

Find the mean absolute deviation.What does it say about the data?

How many pets do you have?0, 1, 5, 0, 3, 1, 0, 2, 2, 6

Guided Practice

Find the mean absolute deviation.What does it say about the data?

How many pets do you have?0, 0, 0, 1, 1, 2, 2, 3, 5, 6

Guided Practice

Find the mean absolute deviation.What does it say about the data?

How many pets do you have?0, 0, 0, 1, 1, 2, 2, 3, 5, 6

Mean is 2

Guided Practice

Find the mean absolute deviation.What does it say about the data?

How many pets do you have?0, 0, 0, 1, 1, 2, 2, 3, 5, 62 2 2 1 1 0 0 1 3 4

How far from 2??

Guided Practice

Find the mean absolute deviation.What does it say about the data?

How many pets do you have?0, 0, 0, 1, 1, 2, 2, 3, 5, 6

16 ÷ 10 = 1.6 MAD is 1.6

Quick Quiz

What is the mean absolute deviation of each data set and what does it mean?

How many pairs of shoes do you own?3, 7, 2, 8, 3, 19, 5, 9

How many books did you read this summer?3, 6, 2, 3, 3, 1, 0, 5, 4, 3

Quick Quiz

How do you describe the spread of data?

In this lesson you will learn how to summarize the spread of data with a single number by calculating and examining the range and mean absolute

deviation of the data.

How many books did 6th graders at Taylor Middle School read this summer?

Reading a line plot

Sometimes students confuse the mean and the mean absolute deviation.

Mean Mean Absolute Deviation

Center Spread

Finding the Range

5-0 5

Comparing the Range and the Mean Absolute Deviation

Range = 5 Mean Absolute Deviation = 1.5

Find the range and mean absolute deviation of this data. How can we use these to describe the spread of data?

Find the range and mean absolute deviation of this data. How can we use these to describe the spread of data?

Range is 6

MAD is 1.6

Find the range and mean absolute deviation of this data. How can we use these to describe the spread of data?

Find the range and mean absolute deviation of this data. How can we use these to describe the spread of data?

Range is 10

MAD is 2.12

Find the range and mean absolute deviation of this data. How can we use these to describe the spread of data?

How many pairs of shoes do 6th graders at Wilson Junior High School own?

Find the range and mean absolute deviation of this data. How can we use these to describe the spread of data?

How many pairs of shoes do 6th graders at Wilson Junior High School own?

Range is 18

MAD is 3.07