A survey of the average amount of cents off that coupons give was done by randomly surveying one coupon per page from the coupon sections of a recent San Jose Mercury News. The following data were collected: 20; 80; 50; 65; 30; 55; 40; 40; 30; 55; $1.50; 40; 65; 40. Assume the underlying distribution is approximately normal. NOTE: If you are using a Student's t-distribution, you may assume that the underlying population is normally distributed. (In general, you must first prove that assumption, though.) Construct a 95% confidence interval for the population average worth of coupons. (i) State the confidence interval. (Round your answers to two decimal places.) (l:ll:l) (ii) Sketch the graph. g: :1 \"em =E :l't : NI (iii) Calculate the error bound. (Round your answer to two decima places.) E (C