Question

According to the American Red Cross, 8.9% of all Connecticut residents have Type B blood. A random sample of 16 Connecticut residents is taken.

X = the number of CT residents that have Type B blood, of the 16 sampled.

What is the expected value of the random variable X?

Answer 1

This is a binomial distribution with $n=16,p=0.089.$

$E(X)=np=16*0.089=1.424.$