7. (8-SU) 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. Find lower

and upper estimates for the total amount of oil that leaked out in 10 hours.

t (h)

0

r(t) (L/h) 8.7

7.6

4

6.8

6

6.2

5.7

10

5.3