Oil leaked from a tank at a rate of r(t) liters per hour. The rate decreased as time passed, and values of the rate at two-hour time intervals are shown in the table. t (h) 0 2 4 6 8 10 r(t) (L/h) 8.8 7.5 6.9 5.2 5.6 5.1 Find lower and upper estimates for the total amount of oil (in liters) that leaked from the tank over the interval [0, 10]. (Use five equal subintervals.) lower estimate L upper estimate L