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