Explore BrainMass


Please see the formula sheet and standard normal distribution table to be used.

Only use a scientific or graphing calculator (Excel does not help me) and please show all working out.

Question 8
A recent study showed that 75% of all people over 60 years of age wear eye glasses. If a random sample of five persons over the age of 60 is selected, what is the probability that
a. none of the five wear eye glasses?
b. at most two of the five wear eye glasses?

Question 9
Waiting times to receive service at a popular fast-food restaurant during the early morning rush period are approximately normally distributed with a mean of 3.5 minutes and a standard deviation of 1.5 minutes.
a. What is the probability that a randomly selected customer has to wait exactly three minutes?
b. What is the probability that a randomly selected customer will have to wait between 4.25 and 5.375 minutes?
c. Seventy-five percent of customers will wait less than what amount of time to receive service?

Question 10
The failure rate on a driver's test is 25%. If 200 people take the test, what is the probability
a. that 60 or more will fail the test?
b. that exactly 40 will fail the test?


Solution Summary

Complete, Neat and Step-by-step Solutions are provided in the attached file.