14. A dentist is trying to decide if there is a difference in the number of weeks three different toothbrushes last. Fifteen patients were randomly assigned to three brands of toothbrushes and the...

Extracted text: 14. A dentist is trying to decide if there is a difference in the number of weeks three different toothbrushes last. Fifteen patients were randomly assigned to three brands of toothbrushes and the number of weeks that Brand Weeks of Wear А 3 4 6. 3 4 B 3 the toothbrushes lasted is given. At the 0.05 5 4 6. significance level, is there a difference in the mean length of time the toothbrushes lasted? a. State the null and alternate hypotheses. Ho: Hj: b. State the decision rule. c. Compute the value of the test statistic. с. Analysis of Variance Source DF SS MS Factor 16.93 8.47 Error 12 18.00 1.50 Total 14 34.93 d. What is your decision regarding the null hypothesis? Interpret the result.