August MPG by tank fill-ups

Fill-up date: 8/7/2010
Miles traveled: 428.3
Trip Est. mpg: 49.9
Fill-up gal.: 9.1
Fill-up mpg: 47.1
Average mpg: (47.1 + 49.9)/2 = 48.5

Fill-up date: 8/15/2010
Miles traveled: 368.9
Trip Est. mpg: 50.5
Fill-up gal.: 7.7
Fill-up mpg: 47.9
Average mpg: (47.9 + 50.5)/2 = 49.2

Fill-up date: 8/26/2010
Miles traveled: 372.8
Trip Est. mpg: 50.2
Fill-up gal.: 7.8
Fill-up mpg: 47.8
Average mpg: (47.8 + 50.2)/2 = 49.0