A tire company finds the lifespan for one brand of its tires

A tire company finds the lifespan for one brand of its tires is normally distributed with a mean of 46,800 miles and a standard deviation of 4000 miles. If the manufacturer is willing to replace no more than 10% of the tires, what should be the approximate number of miles for a warranty?

Solution

Hence warranty should be only for more than 56120 miles