1. A GEICO Direct magazine had an interesting article concerning the percentage of teenage motor vehicle deaths and the time of day. The following percentages were given from a sample. Time % 12-3AM 17 3-6AM 8 6-9AM 8 9AM-noon 6 Noon-3PM 10 3-6 PM 16 6-9 PM 15 9PM-12AM 19

2. Is the percentage of teenage motor vehicle deaths the same for each time period? Conduct a hypothesis test at the 1% level. H o : The percent of teenage motor vehicle deaths is the same for each time period. H a : The percent of teenage motor vehicle deaths is not the same for each time period.

3. The table contains the observed (O) percentages. If the null hypothesis is true, the expected percentages (E) are 100% divided by 8 time periods or 12.5%. A Goodness-of-Fit Test is always right-tailed. The degrees of freedom (df) = n – 1 = 8 – 1 = 7

4. Distribution for the Test: Chi-Square Mean of the distribution = number of dfs = 7 To find the test statistic: Enter Observed values into L1 and Expected values into L2. Quit out of Edit. Press 2 nd, LIST, scroll right to MATH, scroll down to sum(, press Enter. Type (L1 – L2)^2/L2), Enter. The test statistic is calculated. To find the pvalue: Press 2 nd, DISTR, scroll down to Chi-Square cdf, press Enter. Type 13.6,1E99,7), Press Enter. (test statistics, infinity, df) The pvalue is given.

5. Test statistic: 13.6 p-value: 0.0588

6. Decision: Do not reject the null hypothesis. Conclusion: There is NOT sufficient evidence to conclude that the percent of teenage motor vehicle deaths is the same for each time period.