I have read and re-read the chapter on confidence intervals but I can't seem to grasp the concept. Please help!!
During the Rose Bowl, the length (in seconds) of 12 randomly chosen commercial breaks during timeouts (following touchdown, turnover, field goal, or punt) were
65 75 85 95 80 100 90 80 85 85 60 65
(a) Assuming a normal population, construct a 90 percent confidence interval for the mean length of a commercial break during the Rose Bowl.
(b) What are the limitations on your estimate?
How could they be overcome?