Practice Z-Score in Math
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
A z-score measures how many standard deviations a data value is above or below the mean: z = (x - \mu)/\sigma.
A universal measuring stick—z = 2 means '2 SDs above average.'
Example 1
easyA student scored 82 on an exam where the mean was 74 and the standard deviation was 8. What is the student's z-score?
Example 2
mediumOn Test A, Maria scored 78 (\mu = 70, \sigma = 5). On Test B, she scored 85 (\mu = 80, \sigma = 10). On which test did she perform relatively better?
Example 3
easyA data point has value 45 in a distribution with \mu = 50 and \sigma = 4. Find its z-score.
Example 4
mediumIn a class, test scores have mean 70 and standard deviation 8. What raw score corresponds to a z-score of 1.25?