Measures of Dispersion

Which of the following is not a measure of dispersion?

• range

• variance

• standard deviation

• mode

Find the standard deviation for the following data; 86, 95, 78, 67, and 85.

• 82.2

• 5

• 9.33

• 10.43

Find the interquartile range of the data:

20, 22, 25, 29, 31

• 30

• 21

• 25

• 9

The diagram below shows a box plot. Determine the interquartile range.

• 10

• 15

• 20

• 25

Calculate the variance and the standard deviation of the set of the data

• Variance = 3.25, Standard deviation = 1.80

• Variance = 1.64, Standard deviation = 1.28

• Variance = 8.95, Standard deviation = 2.99

• Variance = 12.2, Standard deviation = 3.49

The Variance of a data is 2.5. Find the new variance if each data is multiplied by 3.

• 22.5

• 7.5

• 13.5

Even if each number in a set of the data is added with a constant value, the value of the variance keeps unchanged.

• False

• True

Standard de3viataion is usually used to compare two sets of data. If the value of the standard deviation is very small the data is more

• dispersed

• consistent

• random data

Given the range is 5, if each data is multiplied with 3, what is the value of new range?

• 5

• 8

• 10

• 15

Find the mean of the following data.

13, 35, 33, 47, 38, 37, 42, 16, 14

• 32.55

• 30.56

• 31.55

• 31.56