Question

Each week during the college football season the top 25 teams are ranked based on voting by sportswriters. Many recent upsets of top-rated teams have led to major changes in the weekly rankings over the past several seasons. Statisticians created a formula for determining a weekly index designed to measure the degree to which the top 25 ranked teams changed from the previous week. The greater the index, the greater the changes in the ranked teams. The statisticians calculated this index each week of the 15-week college football season for 6 recent seasons. In order to determine whether the rankings tend to change more or less during any of the 15 weeks, as measured by the index, they conducted an ANOVA on the data using a randomized block design. Here, weeks were considered the treatments and seasons were the blocks. The ANOVA summary table is provided. Complete parts a through d below Click the icon to view the ANOVA summary table c. Tukey's multiple comparisons method was applied to compare the mean index across the 15 weeks. How many pairwise comparisons are involved in this analysis? (Simplifty your answer) d. Using an experimentwise error rate of 0.05, Tukey's analysis revealed that the last week of the regular season had a significantly smaller mean index than week 12. All other pairs of means were not significantly different. Use this result to make a comment about whether the rankings tend to change more or less during any of the 15 weeks in a season. Select the correct choice below and, if necessary, fill in the answer boxes to complete your choice A. The rankings tend to change more in week(s and less in week(s) (Type whole numbers. Use commas to separate answers as needed.) O B. The rankings do not tend to change more or less during any week. ANOVA summary table 1 Source df MS p-Value Weeks 14 3,359.98 240.00 2.39 0.0088 Seasons 5 3,079.25 615.85 6.130.0000 Error 70 7,032.97 100.47 89 13,472.2 Total PrintDone

Answer 1

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