Thread: word problem; oil consumption

please help; i tried to do the riemmans rule, integrate it, trapezoid rule and i cant seem to get the answer.

A diesel generator run continuously consuming oil at a gradually increasing rate until it must be temporarily shut dow to have the filter replaced.

Oil consumption rate on each of the day during the week: (liters per hour)

Sun: .019
Mon: .020
Tue: .021
Wed: .023
Thur: .025
Frida: .028
Satu: .031
Sun: .035

a.) Give an upper estimate and lower estimate for the amount of oil consumed during that week

Please demonstrate your efforts. What did you get for the lower bound?