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: The average value of a function on the interval is determined by The efficiency (in %) of an automobile engine is given by , where is the speed (in km/h) of the car. Find the average efficiency with respect to the speed for s=32km/h to s=86km/h. Round the answer to one decimal place