The Time Between Calls to an Emergency 911-Call Center Is

Multiple Choice

The time between calls to an emergency 911-call center is exponentially distributed with a mean time between calls of 645 seconds. Based on this information, what is the probability that the time between the next two calls is between 200 and 400 seconds?

A) Approximately 0.47
B) About 0.199
C) About 0.747
D) About 0.801