Answer:
0.4353 = 43.53%
Step-by-step explanation:
The times are exponentially distributed, so let's call n the mean, and x the time of transaction. The times of the transaction occurs in a certain time is:
So, the probability that a car complete the transaction in less than 4 minutes, is 1 less the times it does it at 4 minutes:
P = 1 -
P = 0.4353
P = 43.53%