How was the PVF (20%) calculated?

Required Rate of Return = Risk Free rate + (risk premium * beta) = 7.4 + (7 * 1.8) = 20% Calculation of Value of common stock: Year Cash Flow PVF (20%) PV of Cash Flow 2011 $3.2 0.8333 $2.67 2012 $4.48 (3.2 * 140%) 0.6944 $3.11 2013 $5.824 (4.48 * 130%) 0.5787 $3.37 2014 $7.28 (5.824 * 125%) 0.4822 $3.51 2015 $8.736 (7.28 * 120%) 0.4019 $3.51 2015 $78.624 (8.736(108%) / (0.2-0.08)) 0.4019 $31.60 $47.77 Value of Common Stock = $47.77

look at last problem i posted