A consumer organization wants to estimate the actual tread wear index of a brand name of…

A consumer organization wants to estimate the actual tread wear index of a brand name of tires that claims “graded 250” on the sidewall of the tire. A random sa of n -22 indicates a sample mean tread wear index of 242.2 and a sample standard deviation of 21.7 Complete parts (o) through (c) a. Assuming that the population of tread wear indexes is normally distributed, construct a 90% confidence interval estimate mple of the population mean tread wear in ex for tires produced by this manufacturer under this brand name. sus (Round to two decimal places as needed)