I need help solving this discrete math problem

Question

An urn contains four red balls and three blue balls. Draw four balls at random from the urn, without replacement. Compute the expected number of red balls in your sample. (Round to four decimal places.)

Answer 1

The expected value is the same whether sampling with or without replacement: np, where p is the probability for a single sample. The variance, on the other hand, is reduced when sampling without replacement.

Thus, the expected value is 4 * 4/7 = 16/7

16/7 =2.285714 (repeat of the 6 digits after the decimal), which rounds to 2.2857.