There are four entrances to the Government Center Building in downtown ...

        There are four entrances to the Government Center   Building in downtown Philadelphia. The building maintenance supervisor would   like to know if the entrances are equally utilized. T investigates, 400   people were observed entering the building. The number using each entrance is   reported below. At the .01 significance level, is there a difference in the   use of the four entrances?         Entrance                   Frequency    Main   Street                 140     Broad   Street              120     Cherry   Street                 90     Walnut   Street                 50     Total                           400