investment management

Explain in detail and clearly. please do not use excel, do not write nonsense on my post. thank you

20. Consider an equal-weighted portfolio that comprises two assets: A and B. The monthly returns for each asset for the first four months of the year are given below. Month 1 Month 2 Month 3 Month 4 Asset A return 5% -2% -3% -6% Asset B return 4% 1% ? 2% If the effective annual rate of return on the equal- weighted portfolio calculated from the geometric sum of monthly portfolio returns is 19.49%, what is the Month 3 return for asset B