The Business School at State University currently has three parking lots, each containing 155 spaces. Two hundred faculty members have been assigned to each lot. On a peak day, an average of 70% of all lot 1 parking sticker holders show up, an average of 72% of all lot 2 parking sticker holders show up, and an average of 74% of all lot 3 parking sticker holders show up.

a. Given the current situation, estimate the probability that on a peak day, at least one faculty member with a sticker will be unable to find a spot. Assume that the number of people who show up at each lot is independent of the number of people who show up at the other two lots. (Hint: Use the RISKBINOMIAL function.)

b. Now suppose the numbers of people who show up at the three lots are correlated (correlation 0.9).

Does your solution work as well? Why or why not?