Assume you are to invest 70% of the money in the first security and 30% in the second security.

Date	MSFT	GM	S&P 500		MSF Return	GM Return	S&P 500 Return	Portfolio Return
7/31/2017	68.09474	32.14819	2,470.30
8/31/2017	70.40673	32.64856	2,471.65		3.40%	0.015564	0.000546
9/29/2017	70.14307	36.44727	2,519.36		-0.37%	0.116352	0.019303
10/31/2017	78.32597	38.79404	2,575.26		0.11666	0.064388	0.022188
11/30/2017	79.65625	38.89334	2,647.58		0.016984	0.002559	0.028083
12/29/2017	80.95277	37.33445	2,673.61		0.016276	-0.04008	0.009832
1/31/2018	89.91492	38.62781	2,823.81		0.110708	0.034642	0.056179
2/28/2018	89.15827	35.84069	2,713.83		-0.00842	-0.07215	-0.03895
3/29/2018	86.78124	33.4358	2,640.87		-0.02666	-0.0671	-0.02688
4/30/2018	88.92057	33.80383	2,648.05		0.024652	0.011007	0.002719
5/31/2018	94.38628	39.28753	2,705.27		0.061467	0.162221	0.021608
6/29/2018	94.16663	36.56757	2,718.37		-0.00233	-0.06923	0.004842

Calculate the portfolio return