Answer Happy

Two popular brands of tires for tractor-trailers are the Puma and the Eternal. Keiko is a buyer for a major shipping company and wants to estimate the difference between the mean distance (in thousands of km) driven on Puma tires before they need to be replaced and the mean distance (In thousands of km) driven on Eternal tires before they need to be replaced. In the company's testing lab, Keiko tests a random sample of 13 Puma tires and a random sample of 15 Eternal tires. (These samples are chosen Independently.) For the Puma tires, the sample mean distance (in thousands of km) until they would need to be replaced is 57.38 with a sample variance of 6.50. For the Eternal tires, the sample mean distance (in kom) until they would need to be replaced is 51.73 with a sample variance of 70 8. Assume that the two populations of distances driven are approximately normally distributed. Loe Hy be the population mean distance in thousands of km) driven on Puma tires before they need to be replaced. Lot Hy be the population mean distance (in thousands of km) driven on Eternal tires before they need to be replaced Construct a 90% confidence interval for the difference Hi-Then find the lower and upper limit of the 90% conndence interval Carry your intermediate computations to three or more decimal places. Round your answers to two or more decimal places. (If necessary, consulta 182, of formulas) Lower limit: 0 5 ? Upper limiti