In a car crash experiment, cars are classified into one of four groups: subcompact, compact, midsize, and full-size. There are five different cars in each group. Head injury data (in hic, which are standard head injury condition units) for the dummies in the driver's seat are listed in the accompanying table. Use a 0.05 significance level. Test the null hypothesis that the different weight categories have the same mean. Do the sample data suggest that larger cars are safer? Use technology to calculate the test statistic F=? (round to two decimal places), What is the P-value? (round to three decimal places). State the conclusion, do the sample data suggest that larger cars are safer?

Subcompact: 681 428 917 898 520

Compact: 643 655 442 514 525

Midsize: 469 527 525 454 259

Full-size: 384 656 602 787 360