MAD
Mean 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 = 24
24 ÷ 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
Find the mean absolute deviation.
2
2
2
1
1
1
0
0
1
2
3
+3
18 18 ÷ 12 = 1.5
2
2
2
1
1
1
01 2
0
3
3
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
38 ÷ 10 = 3.8
3
2
1
MAD is 3.8
0
1
6
12
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, 6
2 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.
Reading a line plot
How many books did 6th graders at Taylor Middle School
read this summer?
Sometimes students confuse the mean and
the mean absolute deviation.
Mean
Center
Mean Absolute Deviation
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?
Range
is 18
MAD is
3.07
How many pairs of shoes do 6th graders at
Wilson Junior High School own?