4. A quality control expert believes that the life of her firm’s tires is normally distributed with a standard deviation of 15225 miles. A random sample of 10 tires gives the following mileage on the life of the tires. 55000, 48000, 73000, 51000, 77000, 52000, 38000, 41000, 68000, 62000 Construct a 95% confidence interval for the mean life of the tires.
