Question

the probability of fin ding a person having hepatitis is o.15. if we take a sample of 300 people, find the center of the sampling distribution

Answer 1

Here are some hints:

Let p=0.15; it's the probability that someone chosen at random from a group will turn out to have hepatitis.

Let n=300; it's your sample size.

Please see http://math.stackexchange.com/questions/226237/expected-value-of-a-binomial-distribution; the formula for "expected value of a binomial distribution" is right there.