Suppose that the weekly sales volume y (in thousands of units sold) depends on the price per unit (in dollars) of the product according to the following formula y 31(3p + 1)-25, p o (a) what is the rate of change in sales volume when the price is $207 (round your answer to three decimal places.) dys (b) interpret your answer to part (a). (round your answer to the nearest whole number.) if the price increases $1, the sales volume will decrease by ni