During an E-coli scare, HEB purchases 50 heads of lettuce from a local producer. An HEB employee is tasked with inspecting 10 heads of lettuce randomly chosen from this batch of 50 for E-Coli contamination. (a) If 5 of the heads of lettuce are actually contaminated, name the pmf of the number of heads of lettuce the inspector inspects that are contaminated. Use R to calculate the probability that the inspector nds at least 2 contaminated heads. (b) If there are 500 heads of lettuce (instead of 50) of which 150 are contaminated, approximate the pmf of the previous problem by a simple pmf. For this problem, use R to compare the exact probability of the inspector nding at least 2 contaminated heads with the approximate value.