Assume that a sample of size 900 is to be taken from a population that contains 34% people older than 50.
a) What is the probability that the sample will contain at least 290 people older than 50?
b) What is the probability that the sample will contain between 290 and 330 people older than 50?
c) What is the standard deviation of the number of people over age 50 in the sample?