The manufacturing of the X-15 steel-belted radial tire claims that the mean mileage the tire can be driven before the tire wears out is 60,000 miles. The standard deviation of the mileage is 5,000 miles. The Crosset Truck Company bought 48 tires and found that the mean mileage for their trucks is 59,500 miles. Is Crosset's experience different from that claimed by the manufacturer at the .05 significant level?