Normal Distribution Skills Quiz

A test score is at the 60th percentile. If the mean score is 70 and the standard deviation is 10, what is the z-score corresponding to the 60th percentile?

• 0.25

• 0.84

• -0.25

• -0.84

Tags

CCSS.HSS.ID.A.4

If a data point is 1.5 standard deviations above the mean in a standard normal distribution, what is its z-score?

• 1

• 1.5

• 0.5

• 2

What is the probability of a z-score being less than 0 in a standard normal distribution?

• 0.5

• 0.25

• 0.75

• 1

Tags

CCSS.HSS.ID.A.4

Using the empirical rule, what percentage of data falls within one standard deviation of the mean in a normal distribution?

• 68%

• 95%

• 99.7%

• 50%

Tags

CCSS.HSS.ID.A.4

If the mean of a dataset is 100 and the standard deviation is 20, what percentage of the data falls between 80 and 120 according to the empirical rule?

• 68%

• 95%

• 99.7%

• 50%

Tags

CCSS.HSS.ID.A.4

A score of 85 on a test corresponds to a z-score of -1. What is the mean of the test scores if the standard deviation is 15?

• 100

• 70

• 85

• 115

Tags

CCSS.HSS.ID.A.4

What is the probability of a z-score being greater than 2 in a standard normal distribution?

• 0.0228

• 0.9772

• 0.5

• 0.95

Tags

CCSS.HSS.ID.A.4

If a data point is 2 standard deviations below the mean, what is its z-score?

• 2

• -2

• 0.5

• -0.5