A company determines that monthly sales S(t), in thousands of dollars, aftert months of marketing a product is given by 8(t) = 2t3 - 50t2 + 220t + 160. a) Find 8"(1), 8"(2), and S'(4). b) Find S\"(1), S\"(2), and S\"(4). c) interpret the meaning of your answers to parts (a) and (b). (E (a) First, find S'(t). S'(t)= D