Question

Cars enter a car wash at a mean rate of 3 cars per half an hour. What is the probability that, in any hour, no more than 3 cars will enter the car wash? Round your answer to four decimal places.

Answer 1

We have been given a mean rate of cars entering in an hour. So we can model the number of cars entering at poisson distribution.

X: No. of cars entering in an hour

per half hour

Since

Probability that, in any hour, no more than 3 (means 3 or less than 3) cars will enter the car wash.

We want to know for an hour therefore we will manipulate the values for 1 hour

per hour ..............We multiply by 2 because 2half hours make 1 hour.

no more than 3

=

= 0.0025+ 0.0149 + 0.0446 + 0.0892