In: Statistics and Probability
Problem 1
The time it takes to process phone orders in a gift shop is normally distributed with a mean of 6 minutes and a variance of 4 minutes.
a. what is the probability that a phone order can be processed by at least 5 minutes
b. what is the probability that a phone order can be processed by at most 4 minutes
c. What cutoff value would separate the 10% of orders that take the most time to process?
d. if we take a sample of 4 processed phone orders, what is the probability that the average time taken to process phone calls is more than 7.5 minutes
e. if we take a sample of 4 processed phone orders, what is the probability that the average time taken to process phone calls is between 4.5 and 8.5 minutes