The tread life of a particular brand of tire is a random variable best described by a normal distribution with a mean of 60,000 miles and a standard deviation of 2200 miles. What warranty should the...

The tread life of a particular brand of tire is a random variable best described by a normal distribution with a mean of 60,000 miles and a standard deviation of 2200 miles. What warranty should the company use if they want 96% of the tires to outlast the warranty?