Using the annual returns for NKE and SBUX for the year 2009 to 2019, calculate the average annual return for each stock for the period from 2009 to 2019. Also calculate the return variance of each stock and the covariance between the stocks. Next, assume the two stock form a two-asset portfolio. Calculate the standard deviation and mean return of the two-asset portfolio, assuming the following proportion of SBUX in the portfolio: Please show formulas too.

Proportion of SBUX Portfolio standard deviation Portfolio mean return 0% 10% 20% 30% 40% 50% 60% 70% 80% Proportion of SBUX Portfolio standard deviation Portfolio mean return 0% 10% 20% 30% 40% 50% 60% 70% 80%