Compute a simple aggregate price index. Use 1990 as the base period.(Round your answer to 2 decimal places.) The prices of selected items for 1990 and 2009 follow. Production figures for those two periods are also given. Solution The Simple aggregate price Index is given by the formula Simple aggregate price Index = [(?P1)/(?P0)]*100 = [(0.76+2.50+26.00+490.00)/(0.287+0.17+3.18+133.00)]*100 = (519.26/136.637)*100 = 380.03 p.s: it was asking for two decimal places.