In a recent sample of 89 used cars sales costs, the sample mean was $6,325 with a standard deviation of $3,154. 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.) SEE ATTACHMENT FOR QUESTIONS

In a recent sample of used cars sales costs, the sample mean was $6,325 with a standard deviation of $3, 154. 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.) + Part (a) + Part (b) Part (c) Construct a 95% confidence interval for the population mean cost of a used car. (i) State the confidence interval. (Round your answers to one decimal place.) Xx ) (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.) X