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

Answer:

34.9%

Step-by-step explanation:

Z1=$\frac{56-75}{8.6}$ = -2.21

F(Z1) = 0.9861

Z2=$\frac{72-75}{8.6}$ = -0.35

F(Z2) = 0.6367

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