Automobile manufacturer Gruman has identified a vehicle quality issue with the bumpers they are using on their mid-size sedan. Customers with these vehicles are suffering substantial damage and repair costs in low-speed impacts to the bumpers. The company has been soliciting proposals for a new collapsible bumper system to upgrade the performance of their sedans to be equal to the industry average of $400 or less in a collision impact of ≤15 miles per hour (mph). Gruman Engineers believe they have found a bumper system that will meet this requirement. To demonstrate it, they crashed six sedans with this bumper into a barrier at 15 mph, submitted them for repairs and recorded the cost of the repairs. The mean and standard deviation of the costs are found to be $458 and $48, respectively. At the α = .05 significance level, does the test data contradict the manufacturer’s claim that the repair cost does not exceed $400?