Question

Raul received a score of 77 on a history test for which the class mean was 70 with a standard deviation of 10. He received a score of 80 on a biology test for which the class mean was 70 with standard deviation 6. On which test did he do better relative to the rest of the class? biology test history test the same

Answer 1

z-score = (X - Mean ) / Standard deviation

For history test,

z = ( 77 - 70) / 10

= 0.7

For biology test,

z = (80 - 70) / 6

= 1.67

Since z-score for the biology test is larger than z-score for history test,

He did better on Biology test relative to rest of the class.