Please solve in excel with formulas for reference!

The Lambda Corporation has the opportunity to invest in any of the following three proposals: If the company can invest in one, two, or three projects, what should it do to maximize the ratio between expected return and standard deviation? (Answer: Take A+B ) E(R)/ ratios: A=5,B=4.4,C=4.28,(A+B)=5.5630,(A+C)=5.2680, (B+C)=4.5735,(A+B+C)=5.2916. Take (A+B)