1. Assume you have the following information on the monthly price of three securities, A, B and C:

date	A	B	C
Jan-20	113	3209	8.79
Feb-20	109	3215	14.81
Mar-20	110	3297	9.71
Apr-20	113	3087	14.86
May-20	114	3101	8.60
Jun-20	101	3066	11.04
Jul-20	120	3284	13.53
Aug-20	123	3111	9.10
Sep-20	116	3133	8.89
Oct-20	114	3150	13.32
Nov-20	112	3043	10.96

1. Calculate the average log returns and standard deviation for each security
2. Assuming the three securities form a portfolio with the following weights: A = 30%, B=50% and C=20%, calculate the average return on the portfolio
3. Calculate the portfolio risk
4. Try to replicate your analysis in Excel