Question

A teacher's grades are normally distributed with a mean of 75 and a standard deviation

of 8.6. What is the probability that a student will score between 56 and 72?

Answer 1

34.9%

Explanation:

Z1=
`(56-75)/(8.6)` = -2.21

F(Z1) = 0.9861

Z2=
`(72-75)/(8.6)` = -0.35

F(Z2) = 0.6367

P(56<X<72)= 0.9862-0.6367= 0.349 = 34.9%