WARTA, the Warren Area Regional Transit Authority, is expanding bus service from the suburb of Starbrick into the central business district of Warren. There are four routes being considered from Starbrick to downtown Warren: (1) via U.S. 6, (2) via the West End, (3) via the Hickory Street Bridge, and (4) via Route 59. WARTA conducted several tests to determine whether there was a difference in the mean travel times along the four routes. Because there will be many different drivers, the test was set up so each driver drove along each of the four routes. Next slide shows the travel time, in minutes, for each driver-route combination. At the .05 significance level, is there a difference in the mean travel time along the four routes? If we remove the effect of the drivers, is there a difference in the mean travel time?
US 6 West End Hickory Rte. 59
John 18 17 21 22
Joe 16 23 23 22
Bob 21 21 26 22
Bill 23 22 29 25
Josh 25 24 28 28
Paul 26 21 22 21
Phil 29 23 25 22
Zollaco 28 25 28 24