CIN: A 3 B 9 C 6 D 4 E 5 Problem 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 f ( x ) dx=f (c )(ba) a The average value of a function on the interval [a ; b] is determined by b 1 Average value= f ( x ) dx ba a The efficiency e (in %) of an automobile engine is given by e=0.768 s0.00004 s 2 , where s is the speed (in km/h) of the car. Find the average efficiency with respect to the speed for s=3{[a]} km/h to s=8{[d]} km/h. Round the answer to one decimal place. Example: if {[a]}=4, then s=34 km/h, and if {[d]}=5 , then 8{[d]}=85 km/h. Solutions require DETAILED supporting work and explanations; answers alone are not sufficient. Please, explain your steps in full sentences and write the text of the questions. Steps and explanations should be easy to read (for example, use a column for steps and a corresponding column for explanations). Define the variables and set their values clearly. Write the formulas before you substitute any values. Number each problem in sequential logical order. You may refer to the textbook examples to see how to solve and present a problem. In summary, your post should not be just another piece of homework, but a place where present your math problems, kind like you would do in an English essay (use of APA where needed, accordingly with the grading rubric). S L=2 1+ 0 4 H2 2 x dx S4