How can I calculate the payout of an Asian option? I would like to know how to solve the mean over the entire lifetime of the option. Please show me how to calculate the following formula with the sample parameters which may be replaced if needed for easier calculation. I just want to understand concepts of the option and the payout formula.

where interest rate r=0, volatility =0.2, T=1, S0=100 v=120

T Sd 0 U u T Sd 0 U u