The Department of Health and Human Services wants to know the average income of general assistance recipients. A sample of 60 recipients shows a sample mean of $ 17,400 with a standard deviation of $ 3,150.
(a) Place a 90% confidence limit around your best estimate of the average income of general assistance recipients.
(b) What is the probability that the average income could be $ 18,500 or more?
(c) What is the probability that the average income might be as low as $ 17,000?