Question

The final exam scores in a statistics class were normally distributed with a mean of 70 and a standard deviation of five. What is the probability that a student scored more than 75% on the exam?

a) 0.95

b)0.68

c) 0.16

d)0.84

Answer 1

for normal distribution z score =(X-μ)/σ
here mean=       μ=	70
std deviation   =σ=	5.0000

probability that a student scored more than 75% on the exam :

probability =

P(X>75)

=

P(Z>1)=

1-P(Z<1)=

1-0.8413=

0.16

option C is correct