12. Suppose the following data are true about the economy of Ghana for a recent year Transfer payments $62 Gross private investment 185 Government purchases 205 Net exports 4 Personal taxes 91 Interest paid by consumers 4 Personal consumption 510 Contribution for social insurance 35 Corporate retained earnings 51 Depreciation 59 Indirect business taxes 47 Net foreign factor income 3 a. Calculate GDP, GNP, NDP, NNP, NI, PI, and DPI. b. If the appropriate price index is 115, calculate the real GDP