Assume a binomial probability distribution has p = .60 and n = 200.

a)What are the mean and standard deviation (to 2 decimals)?

b)Why can the normal probability distribution be used to approximate this binomial distribution?


c)What is the probability of 100 to 110 successes (to 4 decimals)?


d)What is the probability of 130 or more successes (to 4 decimals)?


e)What is the advantage of using the normal probability distribution to approximate the binomial probabilities?

1 answer

a. mean = np = 200(.6) =120
Standard deviation = sqrt((.6*.4*200))= sqrt(48)