The area of a region under a curve is greater than the area of an inscribed rectangle and less than the area of a circumscribed rectangle. Intuitively, we understand that somewhere "between" the inscribed and circumscribed rectangles there is a rectangle whose area is precisely equal to the area of the region under the curve:

b

a

f(x)dx=f(c)(ba)

The average value of a function on the interval[a;b]

is determined byAveragevalue=1

ba

b

a

f(x)dx

The efficiencye

(in % ) of an automobile engine is given bye=0.768s0.00004s

3

, wheres

is the speed (in km/h) of the car. Find the average efficiency with respect to the speed fors=3{[a]}

km/h tos=8{[d]}

km/h. Round the answer to one decimal place.