Binomial Model - Normal Approximation

Hi I am stuck on the following question

The Anderson tennis racquet comes in a midsize and an oversize version. From previous history is is known that sixty percent of all customers purchasing a new tennis racquet at a certain large sports store want the oversize version of the particular brand.

what is the probability that more than 32 customers in a random sample of 40 will purchase the oversized tennis racquet?

any help would be great!

Re: Binomial Model - Normal Approximation

estimate that probability with P(N>32.5)

where N is a normal random variable with mean np=(40)(.6) and variance npq.