In a car crashexperiment, cars are classified into one of fourgroups: subcompact,compact, midsize, andfull-size. There are five different cars in each group. Head injury data(in hic, which are standard head injury conditionunits) for the dummies in thedriver'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 aresafer?

calculate the test statistic F.

F=