The cost function for manufacturing electric drills is estimated to be: C(x) = 2x - 5x + 338. Where C(x) is in dollars, and x is drills manufactured per hour. The average cost function is defined by AC = C(X) (a) Find the average cost function. AC = (b) What is the average cost (to the nearest penny) of producing 5 drills per hour? per drill. (c) What is the average cost (to the nearest penny) of producing 12 drills per hour? $ (d) Using Excel, find the number of drills per hour that should be produced to minimize average cost. drills per hour (e) What is the minimum average cost to the nearest penny? $ per drill per drill