Question: The waiting times to see a teller at a certain bank on Saturday mornings are approximately normally distributed with a mean of 2.9 minutes and a standard deviation of 2.1 minutes. Use z-scores to address the following:

Find the probability that a randomly selected bank customer on a Saturday morning has to wait

a) less than 2.4 minutes?

b) more than 5 minutes?

c) Find the value of the 85th percentile of the waiting times. Interpret what this X value means relevant to the problem.

d) Find the time that no more than 5 percent of the customers have to wait.