Assume every bus in Gainesville follows an exponential distribution with a mean of 7.5 minutes. From a bus stop, we randomly survey 100 different buses (i.e., not of the same line). Calculate the probability that a specific bus (say, line 34) passes from the bus stop in the next 10 minutes. Then, calculate the probability that the mean of all the buses is less than 10 minutes. Explain the result, does it make sense?