The arrival time for a delivery driver in Canberra is exponentially distributed with a mean of 25 minutes.   1) What is the probability that the arrival time will exceed 30 minutes?   2) What proportion of arrivals will be completed within 20 minutes?

Solve step by step in digitl format At the General Hospital Dr. Manuel Gea González, of the Ministry of Health, it is recorded that, on average, an ambulance arrives every ten minutes. Assuming an exponential distribution, determine:a) What is the probability that the next ambulance will arrive in 15 minutes or less?b) What is the probability that the next ambulance will arrive in more than 25 minutes?c) What is the probability that the next ambulance will arrive in more than 15 minutes, but less than 25?

A professor knows that her statistics students' final exam scores have a mean of 79 and a standard deviation of 12.4. In his class, an "A" is any exam score of 90 or higher. This quarter she has 25 students in her class. What is the probability that 7 students or more will score an "A" on the final exam?

The manager of a gas station has observed that the times required by drivers to fill their car's tank and pay are quite variable. In fact, the times are exponentially distributed with a mean of 7 minutes. What is the probability that a car can complete the transaction in less than 4 minutes? Probability =