You plan to invest 31% of your portfolio in Company A with the remainder to be invested in Company B. The standard deviation of Company A's stock returns is 19%. The standard deviation of Company B's stock returns is 21%. The correlation between the stock returns of Company A and Company B is 0.8. What is the standard deviation of your portfolio's returns (as a percentage to two decimal places)? Your answer should be expressed as a percentage to 2 decimal places but do not include a percent sign. For example, if your answer is 10.237%, you should enter 10.24. If your answer is 10.233\%, you should enter 10.23. Please do not enter your answer as a decimal, such as 0.1024