posted by Jimmy
The function f is continuous on the interval [4, 15], with some of its values given in the table above. Estimate the average value of the function with a Trapezoidal Approximation, using the 4 intervals between those given points.
x 4 9 11 14 15
f(x) -6 -11 -18 -21 -25
for each trapezoid number i the area is
(f(x_i)+f(x_i+1))/2 * (x_i+1 - x_i)