Suppose that the length of long distance phone calls, measured in minutes, is known to have an exponential distribution with the average length of a call equal to $18 minutes. The probability that the...

Suppose that the length of long distance phone calls, measured in minutes, is known to have an exponential distribution with the average length of a call equal to $18 minutes.

1. The probability that the length of a phone call is between 14 and 19 is P(14 ≤ x ≤ 19) =


2. The 68th percentile is a phone call that lasts minutes.