An NBA player makes a successful free-throw 80% of the time. Find the probability that he is successful exactly 4 times in 5 attempts?

Answer 1

Binomial probability function:

P(x) = (nCx)(p^x)[q^(n-x)]

x = 4
n = 5
p = .8
q = 1 - p = .2

With your data:

P(4) = (5C4)(.8^4)[.2^(5-4)]

I'll let you finish the calculation.