CK-12 Probability and Statistics - Advanced

5.1. The Standard Normal Probability Distribution http://www.ck12.org

2.z≈ 0. 32

3.z≈ 1. 90

4.z≈ 3. 02

2. Because the data is normally distributed, students should use the 68− 95 − 99 .7 rule to answer these questions.
   
   
   1. about 16% (less than one standard deviation below the mean)
   
   
   2. about 95% (within 2 standard deviations)