Assume that it costs a company approximately C(x) = 400,000 + 160x + 0.003x? dollars to manufacture x smartphones in an hour. (a) Find the marginal cost function. Use it to estimate how fast the cost is increasing when x - 10,000 $ per smartphone Compare this with the exact cost of producing the 10,001st smartphone. The cost is increasing at a rate of $ per smartphone. The exact cost of producing the 10,001st smartphone is $ ). Thus, there is a difference of $ (b) Find the average cost function C and the average cost to produce the first 10,000 smartphones. (X) - (10,000) = $ (9) Using your answers to parts (a) and (b), determine whether the average cost is rising or falling at a production level of 10,000 smartphones The marginal cost from (a) is-Select- than the average cost from (b). This means that the average cost is --Select-- at a production level of 10,000 smartphones