# Calculating Averages and Probability

If customers arrive at a single drive-in window at a local bank one every four minutes on the average, and if you can serve a customer in three minutes on the average:

a. How long should customers expect to be at the bank facility on the average?

b. How many cars would we expect to be in the drive-in facility on the average?

c. What is the probability that four or more cars will be in the drive-in facility?

https://brainmass.com/business/business-math/calculating-averages-probability-414862

#### Solution Preview

If customers arrive at a single drive-in window at a local bank one every four minutes on the average, and if you can serve a customer in three minutes on the average:

Arrival rate = ...

#### Solution Summary

This solution is comprised of a step by step response which provides computations for average calculations based on time and number, and a probability calculation. All required formulas are provided.