x 0 1 2 3 4 5 6 7 8 9 10

f(x) 20 19.5 18 15.5 12 7.5 2 -4.5 -12 -20.5 -30

some values of a continuous function are given in the table above. The Trap. Rule approximation for (bounds zero to ten) ∫ f(x)dx is

a)7.5

b) 32.5

c)33.325

d)33.333

e) 57.5

I'm not sure if I'm setting the problem up correctly because my answer's different from the answers above.