Percentiles on Standard Normal Curve

Which z-score represents the 95th percentile?

• 1.645

• -1.645

• 0.8289

• -0.8289

Which z-score represents the third quartile?

• 0.7734

• 0.67

• -0.67

• -0.7734

Which z-scores contain the center 60% or the data?

• -0.25 and 0.25

• -0.84 and 0.84

• -0.25 and 0.25

• -0.5987 and 0.5987

IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. What is the lowest score possible to be in the top 10%?

• 1.28

• -1.28

• 80.8

• 119.2

IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. What is the highest score possible to be in the bottom 30%?

• 92.2

• 107.8

• 0.52

• -0.52

IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. What are the IQ scores that contain the center 90% of the scores?

• -1.645 and 1.645

• -1.28 and 1.28

• 75.325 and 124.675

• 80.8 and 119.2