[16 points] An Internet provider contacts a random sample
of 300 customers and asks how many hours per week the customers use
the Internet. It found the average amount of time spent on the
Internet per week of the sample participants to be 7.2 hours. The
standard error is 0.458.
(a) Find the margin of error, using the given standard error, for a
99% confidence interval for the average amount of time all
customers use the Internet.
(b) Use the result of part (a) to find the 99% confidence
interval for the parameter. Round to two decimal places and
show work.
(c) Interpret the confidence interval you obtained in part (b) in
an English sentence in the context of the situation.
(d) A claim is made that the average amount of time spent
on the Internet per week is not 7 hours. Give the null and
alternate hypotheses used in a test of this claim.