An active portfolio manager outperformed the benchmark last year by 2.87 %, where the benchmark is the S&P500 index. In analyzing the portfolio for return attribution using the Carhart 4 factor model, you find the following results:

Factor	Portfolio Sensitivity	Benchmark sensitivity	Factor return (%)
RFRF	0.95	1.04	5.52
SMB	-0.96	-1.04	2.21
HML	0.31	0.05	4.67
WML	0.19	0.09	7.75

What was the return to the portfolio resulting from the security selection component?

The answer is 12

Please show how to get that in excel