7. Use both numerical and graphical methods to find the multiplier effect of the following shift in the consumption function in an economy in which investment is always $220, government purchases are always $100, and net exports are always –$40. (Hint: What is the marginal propensity to consume?)

Income Consumption before Shift Consumption after Shift

$1,080 $ 880 $ 920 1,140 920 960 1,200 960 1,000 1,260 1,000 1,040 1,320 1,040 1,080 1,380 1,080 1,120 1,440 1,120 1,160 1,500 1,160 1,200 1,560 1,200 1,240