If I have stata and an excel file, how would I calculate these problems with a porfolio of stocks…

If I have stata and an excel file, how would I calculate these problems with a porfolio of stocks where one stock is 50% and the other two are 25%. Could you give me step by step how to go about solving that.

(a) Using the end date 12/31/15 and the three stocks in your portfolio, calculate the annualized return for the last 10 years, 5 years, and 1 year. For example, to calculate the 10-year return, assume you bought the stock on 12/31/09 and sold it on 12/31/19. What is the annualized return? Make the calculations for each stock and for the entire portfolio. Note: Use the adjusted closing price. This price is adjusted for both dividends and splits.

(b) What was the volatility (variance) of the daily return for those same periods?

(c) How do the returns and variance compare with the S&P 500?