In car crash experiments conducted by the National Transportation Safety Administration, new cars were purchased and crashed

Question:

In car crash experiments conducted by the National Transportation Safety Administration, new cars were purchased and crashed into a fixed barrier at 35 miles per hour. The subcompact cars were the Ford Escort, Honda Civic, Hyundai Accent, Nissan Sentra, and Saturn SL4. The compact cars were the Chevrolet Cavalier, Dodge Neon, Mazda 626 DX, Pontiac Sunfire, and Subaru Legacy. The midsize cars were the Chevrolet Camaro, Dodge Intrepid, Ford Mustang, Honda Accord, and Volvo S70. The full-size cars were the Audi A8, Cadillac Deville, Ford Crown Victoria, Oldsmobile Aurora, and Pontiac Bonneville. Head injury data (in hie) for the dummies in the driver's seat are listed below. Use a 0.05 significance level to test the null hypothesis that the different weight categories have the same mean. Do the sample data suggest that larger cars are safer?