Question: Assume you tested sevreral Firestone tires and recorded their failure times (as defined by an engineer). After doing a Chi-Square test , you decided taht failures are normally distributed, with mean failure of 50,000 miles and a standard deviation of 10,000 miles. Determine the following:
a) reliability of the tires at 40,000 miles
b) given that a tire has been driven (on a test machine) 20,000 miles, determine its reliability at 60,000 miles.