. Suppose that Congress enacts a one-time-only 10% tax rebate that is expected to infuse $y…

. Suppose that Congress enacts a one-time-only 10% tax rebate that is expected to infuse $y billion, 5 … y … 7, into the economy. If every person and every corporation is expected to spend a proportion x, 0.6 … x … 0.8, of each dollar received, then, by the multiplier principle in economics, the total amount of spending S (in billions of dollars) generated by this tax rebate is given by S1x, y2 = y 1 – x What is the average total amount of spending for the indicated ranges of the values of x and y? Set up a double integral and evaluate it.