expected value and standard deviation

Question

A basketball player makes each free throw with a probability of .75. If this player attempts 75 shots, find the expected value and standard deviation for the number of made free throws

Answer 1

I think this is a proportion problem, with n=75, p=0.75

 

Expected Value = n*p=75*0.75 = 56.25

 

Variance = p*(1-p)/n = 0.75*(1-0.75) /75 = 0.0025

 

Standard Deviation = √variance = √0.0025 = 0.05