A study of the time spent shopping in a supermarket for a market basket of 20 specific items showed an approximately niform distribution between 20 minutes and 40 minutes. What is the probability that the shopping time will be
a. between 25 and 30 minutes
b. less than 35 minutes
c. What are the mean and standard deviation of the shopping time?
6.29 Given an exponential distribution with the mean number of arrivals per unti = 30, what is the probability that the arrival time is
a. less than x = 0.1?
b. greater than x = 0.1?
c. between x = 0.1 and x = 0.2?
d. less than x = 0.1 or greater than x = 0.2?
6.33 Telephone calls arrive at the information desk of a large computer software company at a rate of 15 per hour.
a. What is the probability that the next call will arive within 3 minutes (0.05 hour)?
b. What is the probability that the next call will arrive within 15 minutes (0.25 hour)?
c. Suppose the company has just introducted an updated version of one of its software programs, and telephone calls are now arriving at a rate of 25 per hour. Given this information, redo (a) and (b).