In a recent sample of 88 used cars sales costs, the sample mean was $6525 with a standard deviation of $3158. 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 cost of a used car. (i) State the confidence interval. (Round your answers to one decimal place.) 5855.9 , 7194.1 (ii) Sketch the graph. = 0.025 C.L. = 0.95 0.025 X X X (iii) Calculate the error bound. (Round your answer to one decimal place.) 669.1