Fill in the missing information in the following table. Assume that Portfolio AB is 50 percent invested in Stock A. (A negative value should be indicated by a minus sign. Do not round intermediate calculations. Enter your answers as a percent rounded to 2 decimal places.) Annual Returns on Stocks A and B Year Stock A Stock B Portfolio AB 2015 13.5 % 23.5% % 2016 36.0 % -36.5% % 2017 -19.0 % 46.5% % 2018 25.5% 16.5% % 2019 14.0% 25.5% % % % % Average return Standard deviation % % %