H W Exercise 8.3 About 7% of Americans have type O-negative blood. Suppose that a random sample of 15 Americans is selected. a. What is the probability that more than 12 have type O-negative blood. b. What is the expected value and standard deviation of the distribution of type O-negative blood in a random sample of 15 Americans?Exercise 8.4 A study indicated that about 35% of workers are uninsured. A random sample of 9 workers is selected. a. Find the probability that no more than at most 3 are uninsured.b. Find the repected value and standard deviation (rounded to 2 decimal places) of the distribution of uninsured workers in a random sample of 9 workers.Exercise 8.8 A survey showed that about 35%% of adults pretend not to be home on Halloween. Suppose that a random sample of 20 adults is drawn. a. What is the probability that no more than 5 pretend not to be home on Halloween? b. Find the expected value and standard deviation