Z-scores: practice

Statistics. Try each one, then open the answer. The Credit Sprint app generates unlimited new versions.

Item 1.

A distribution has mean 65 and standard deviation 5. What is the z-score of the value 57.5?

Show answer

z = (x − mean) ÷ SD = (57.5 − 65) ÷ 5 = -1.5.

Item 2.

A distribution has mean 100 and standard deviation 5. What is the z-score of the value 105?

Show answer

z = (x − mean) ÷ SD = (105 − 100) ÷ 5 = 1.

Item 3.

A distribution has mean 55 and standard deviation 10. What is the z-score of the value 60?

Show answer

z = (x − mean) ÷ SD = (60 − 55) ÷ 10 = 0.5.

Item 4.

A distribution has mean 90 and standard deviation 10. What is the z-score of the value 120?

Show answer

z = (x − mean) ÷ SD = (120 − 90) ÷ 10 = 3.

Item 5.

A distribution has mean 75 and standard deviation 10. What is the z-score of the value 60?

Show answer

z = (x − mean) ÷ SD = (60 − 75) ÷ 10 = -1.5.

Item 6.

A distribution has mean 100 and standard deviation 15. What is the z-score of the value 92.5?

Show answer

z = (x − mean) ÷ SD = (92.5 − 100) ÷ 15 = -0.5.