Measures of Variability (Ungrouped Data)

Which of the following is not a measure of dispersion?

• the range

• the 50th percentile

• the standard deviation

• the variance

Answer explanation

the 50th percentile of the data is a measure of a central location or the median.

What is the range of the following data?

10, 13, 12, 11, 20, 17, 28, 30, 27, 9

• 21

• 20

• 19

• 18

Answer explanation

Range= Highest value- lowest value.

Highest value is 30

Lowest value is 9

R= 30-9= 21

If the range of the scores of the students in a math test is 11 and the lowest score is 10. Find the highest possible score.

• 17

• 19

• 21

• 25

• the variance of the population

• the standard deviation of the sample

• the standard deviation of the population

• the variance of the sample

What is the standard deviation of the scores 5, 4, 3, 6 and 2?

• 3.5

• 3

• 2.5

• 2

It is calculated by computing the mean and then the specific distance between each score and that mean without regard to whether the score is above or below the mean.

• Range

• Average Deviation

• Standard deviation

• Variance

The scores of the students in a 10-item Math test are 7, 8, 9, 10, and 6. What is the average deviation of the scores of the students in a Math test?

• 1.2

• 2.3

• 3.1

• 4.2

If the standard deviation of a data is 10 with a mean of 45. What is the variance of the data?

• 80

• 90

• 100

• 1000

It measures how far each number in the set is from the mean (average), and thus from every other number in the set.

• Range

• Average Deviation

• Variance

• Standard Deviation

The descriptive measure of location which is the most likely to be influenced by extreme values in the data set is the

• Range

• Average Deviation

• Variance

• Standard deviation