What is the probability that 3 or more lines are in use at noon? f) What is the probability that at least 1 line is in use at noon? g) Given that 3 or more lines are in use at noon, what is the probability that all 5 are in use? h) Assuming that each day is independent of the next, what is the probability that on exactly 2 out of the next 5 days there are no lines in use at noon? i) Suppose you come by every day at noon to see how many lines are in use. What are the chances that you don’t find all 5 in use until your 7th visit? j) Find the standard deviation of the number of lines in use this support center expects to have at noon. k) Each call lasts an average of 3.75 minutes. What is the mean and standard deviation of the number of minutes at noon? l) What are the mean and the standard deviation of the total number of lines in use this support center expects to have at noon over a 7-day week? m) If another support center has a mean of 2.1 calls and a standard deviation of 1.8 calls, what is the mean and standard deviation of the total of number of calls of both centers at noon?