Question

The postal service sorts mail as Priority Mail Express, Priority Mail, First-Class Mail, or Standard Mail. Over a period of 3 weeks, 18 of each type were mailed from the Network Distribution Center in Atlanta, Georgia, to Des Moines, lowa. The total delivery time in days was recorded. Minitab was used to perform the ANOVA. The results follow: Source Factor DF MS 68 71 2.07 0.69 2.56 0.062 18.40 0.27 20.47 Erroro 06 Total Level Priority Mail Express Priority Mail First-Class Mail Standard Mail N Mean StDev 18 3.081 0.458 18 2.979 0.632 18 3.430 0.537 18 3.226 0.430 Using the ANOVA results, compare the average delivery times of the four different types of mail 1. Identify the null hypothesis and the alternate hypothesis Null hypothesis: O b 2. Alternate hypothesis H1 : At least one mean is different. H: All means are equal 3. Use the 0.01 significance level to test if this evidence suggests a difference in the means for the different types of mail. HO is There is in the means for the different types of mail

Answer 1

(because the P-value > 0.01)