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, Iowa. The total delivery time in days was recorded. Minitab was used to perform the ANOVA_ The results follow: 2.81 15.87 a. 23 18.68 Source Factor Error Total Priority mail Express Priority mail First-Class Mail Standard mail 18 4.09 2.783 2.995 3.308 3.177 a. elo StoeV e. 386 e. 684 487 e. 282