Newtons a tire manufacturer wanted to set a mileageguarantee on its new Road War

Newtons a tire manufacturer wanted to set a mileageguarantee on its new Road Warrior 60 tire. A sample test of 500tires revealed that the tires mileage is normally distributed witha mean of 50000 miles and a standard deviation of 1750 miles. Thewarranty on the tires is presently set at 47500 miles. The z-teststatistic result was 1.43. The manufacturer wanted to determine ifthe tires were exceeding the guarantee. At the .05 significantlevel it was concluded that the tires are exceeding themanufacturers guarantee.