Question

In her Stats class last semester, Bubbles earned a 80 on her final test (M=85 and s=10). In her Speech class she earned a 44 (M=50 and s=4). In which class did she do better?

Answer 1

Solution :

Given that ,

mean = = 85 ( state class )

standard deviation =  = 10

x = 80

Using z-score formula,

z = x - /   

z = 80 - 85 / 10

z = -0.50 ( state class )

mean = = 50 ( speech class )

standard deviation =  = 4

x = 44

Using z-score formula,

z = x - /   

z = 44 - 50 / 4

z = -1.50 ( speech class )

state class better than speech class, because state class z-score -0.50 is more than speech class z-score -1.50