Z-Score Practice

Find the Z-score.

Mean = 22

Standard Deviation: 3.1

x = 29

• 2.26

• 16.45

• -2.26

• 1.26

Find the Z-score.

Mean = 21

Standard Deviation: 1.3

x = 22

• 0.77

• 5.33

• 1.07

• 1.26

Find the Z-score.

Mean = 27

Standard Deviation: 1.4

x = 11

• -11.43

• 7.85

• -2.33

• 4.16

The sign of the z-score indicates whether the location is above(positive) or below(negative) the mean.

• True

• False

Find the z-scores value corresponding if the location is above the mean by 1/2 standard deviations

• -0.50

• +1.00

• +0.50

• -1.00

A data set has a mean of 20 and a standard deviation of 3. Calculate the z-score for 23.

• It means you did better than zero people.

• It means you scored the same grade as the average grade.

• It means you earned a zero on the quiz.

• It means the average score was a zero.

Use the image of the normal graph provided. What is the value of the mean?

• 6

• 34

• 52

• 70

Use the image of the normal graph provided. What is the value of the standard deviation?

• 6

• 12

• 36

• 18

A data point has a z-score of -2.50. How should be interpret this information?

• This data point is 2.5 standard deviations above the mean

• This data point is 2.5 standard deviations above the median

• This data point is 2.5 standard deviations below the mean

• This data point is 2.5 standard deviations below the median

Answer explanation

A z-score of -2.50 indicates that the data point is 2.5 standard deviations below the mean. This means it is significantly lower than the average value.