Answer Key
z scores and Percentiles Comprehensive Practice
answer key
1. a. Joe was (79 – 74)/6 = 0.83 standard deviations above the mean in Chemistry. Joe was (71 – 60)/8 = 1.4 standard deviations above the mean in English.
b. He did better in English. His performance was further above the mean compared to the other students in the class.
2. 10.7%
3. 89%
4. 78.5%
5. -1.28
6. 1.28
7. -1.645, +1.645
8. a. 14%
b. 33%
c. 24.5%
d. 47.42 inches