2. Assume that the proportion of general people with blood type A is 30%.

(a) Suppose one person is randomly selected. Determine the probability that the person has blood type A, and calculate the expected value and variance.

(b) Suppose 20 persons are randomly selected. Determine the probability distribution of the number of persons with blood type A, and calculate the expected value and variance.

(c) What is the relationship between the distribution in

(a) and the distribution in (b)?