2) Consider the function g (x) = 10 - x over the interval [1, 3]. I want you to approximate the average value of this function over the interval [1, 3] by using four rectangles all of equal width. Use the midpoint of each subinterval to calculate the height of each rectangle. Give exact decimal answers. a) The area of these four rectangles is b) The average value of this function over the given interval is approximated by