Range and Interquartile Range

Mean Absolute Deviation

By Rachel Wright

Measures of Central Tendency

​Review:

Find the mean, median, mode, and range of ​10, 9, 3, 8, 10.

Measures of variation include the IQR (interquartile range) and MAD (mean absolute deviation).​

Mean Absolute Deviation

• Mean absolute deviation describes variation in a data set and is the average distance between each data value and the mean.

• It can be calculated by finding the difference of each data value and the mean and then finding the average of that.

Multiple Choice

What is mean absolute deviation?

• The mean of the data.

• The absolute value of the mean.

• The variation of data values around the mode.

• The average distance between the data values and the mean.

​To find the MAD:

Find the mean of the set of data.

Take each number in the data set, subtract the mean, and take the absolute value.

Then take the sum of the absolute values.​

Then divide the sum by the total number of values in the data set.​

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Subject | Subject

Some text here about the topic of discussion

Example: Find the MAD of 3, 3, 2, 2, 6, 8.​

​

• ​3 + 3 + 2 + 2 + 6 + 8 = 24

• 24 ÷ 6 = 4

• 4 - 3 = 1

• 4 - 3 = 1

• 4 - 2 = 2

• 4 - 2 = 2

• 6 - 4 = 2

• 8 - 4 = 4​

• 1 + 1 + 2 + 2 + 2 + 4 = ​12

• 12 ÷ 6 = 2​

​

The MAD is 2.

Multiple Choice

Find the MAD of 9, 7, 11, 10, 8

• 9

• 1.2

• 6

• 5

Multiple Choice

Find the MAD of 10, 9, 3, 8, 10.

• 3

• 1

• 2

• 5