Suppose Apple claims that the average wait time for a customer calling the Apple Care support line is 175 sec-onds. A random sample of 40 customers had an average wait time of 187 seconds. Assume the population standard deviation for wait time is 50 seconds. Using a 95% confidence interval, does this sample support Apple?

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.