Are these calculations correct to find the ROI, RER, Real Rate of Return and After-tax Rate of Return of an investment ?t.

Over 3 years, an investment of $2500 increases to $3127. Last 36 months (3 years) inflation rate is 6.7 % (1.9+2.3+2.5) The tax rate is 22%. ROR = 7.7% Roi = 25.08% 3127 - 2500 2x 100 = 25.08 2500 - 2500 - 1 = 0.077... Real rate of return = 17.2% After-tax real rate of return = 12% (1+0,1956) (1+0,2508) (1+0,067) 1 = 0.172... (1+0,06711 - 1 = 0.120