Name______

Date______pd_____A orB

Mean Absolute Deviation (MAD)

To find the MAD

1. Find the mean

2. Subtract each data value from the mean

3. Take the absolute value of each value from step #2.

4. Add up all values from step #3.

5. Divide by the number of data values.

To decide which measure of central tendency (mean, median, mode) and which measure of variability (IQR and MAD) is best

1. See which describes the data best. Which number seems to be more in the center of the numbers.

2. If there are outliers, median and IQR will be best.

3. If there are no outliers, choose which number seems to be closer to most of the data values.

1. Find the mean, median, IQR and MAD of the numbers shown below.

80 , 76 , 63 , 92 , 47 , 82 and 76.

Mean = _____ Median = ______IQR = ______MAD = ______

Sometimes it is easiest to put the data in a table like the one below to find MAD. If this works for you, do it for each problem.

MAD worksheet

x / `x / x -`x / ï x -`x ï
80
76
63
92
47
82
76

Which measure of central tendency and measure of variability describe the data best?

2. Find the mean, median, IQR and MAD of the numbers shown below.

4 , 5 , 8 , 7 , 1 , 6 and 10.

Mean = _____ Median = ______IQR = ______MAD = ______

Which measure of central tendency and measure of variability describe the data best?

3. Find the mean, median, IQR and MAD of the numbers shown below.

30 , 35 , 42 , 15 , 87 , and 23.

Mean = _____ Median = ______IQR = ______MAD = ______

Which measure of central tendency and measure of variability describe the data best?

4. Find the mean, median, IQR and MAD of the numbers shown below.

21, 19, 27, 15, 47, 36, 45, and 76.

Mean = _____ Median = ______IQR = ______MAD = ______

Which measure of central tendency and measure of variability describe the data best?

5. Find the mean, median, IQR and MAD of the numbers shown below.

123, 145, 132, 119, 127, 100 and 109.

Mean = _____ Median = ______IQR = ______MAD = ______

Which measure of central tendency and measure of variability describe the data best?

6. Find the mean, median, IQR and MAD of the numbers shown below.

4, 12, 5, 7, 11, 3, 6, and 12.

Mean = _____ Median = ______IQR = ______MAD = ______

Which measure of central tendency and measure of variability describe the data best?

7. Find the mean, median, IQR and MAD of the numbers shown below.

245, 323, 147, 456, 199, 282 and 323.

Mean = _____ Median = ______IQR = ______MAD = ______

Which measure of central tendency and measure of variability describe the data best?

8. Find the mean, median, IQR and MAD of the numbers shown below.

17, 16, 16, 16, 20, 21, 21 and 76.

Mean = _____ Median = ______IQR = ______MAD = ______

Which measure of central tendency and measure of variability describe the data best?