Which forecast is best using mape as accuracy measure

Question

Problem:

A convenience store posted the following figures for gasoline sales in gallons over the past 4 days compared to its forecasted sales using two different forecast methods:

            DAY                ACTUAL SALES                      FORECAST 1               FORECAST 2

             1                                 600                                     610                             570

             2                                 590                                     620                             625

             3                                 570                                     600                             560

             4                                 635                                      590                             615

Required:

Using MAPE as the accuracy measure, which forecast is "best". You must show your work. Solve the given numerical problem and illustrate step by step calculation.