Monthly sales of a particular personal computer are expected to decline at the following rate of S'(t) computers per month, where t is time in months and S(t) is the number of computers sold each month. 2 S'(t)=-20t3 The company plans to stop manufacturing this computer when monthly sales reach 500 computers. If monthly sales now (t = 0) are 1,580 computers, find S(t). How long will the company continue to manufacture this computer? |S(t) =