This is the questions below, need help with homework.

5.68 Marketing and Consumer Behavior Nine West sells women's flip flops in eight different colors. Despite the available selection, 50% of all flip flops purchased are white. Suppose 30 buyers are selected at random. a. Find the mean, variance, and standard deviation of the number of buyers who purchase white flip flops. b. Find the probability that the number of white flip flops purchased will be within two standard deviations of the mean. Compare this with the predicted result from Chebyshev's Rule. c. Suppose two groups of 30 customers are independently selected. What is the probability of at least one group having exactly 15 people who buy white flip flops