_ . Find the minimum value of the average cost for the given cost function on the given intervals. (:00 =x3 + 37x+128 (ansxmo (b) 105x520 is\" w i _ in] T he minimum value of the average cost over the interval 1 5x5 10 is D '9'\" ml in the nearest tenth as needed. Do not include the S s ymboi in your answer.) H"'ii'mum value of the average cost over the interval 10 5x S 20 is - fienearest tenth as needed Do not include the S symbol in your answer.)