jamie plans to build a portfolio containing two investments. assume 40% is invested in a and 60% is invested in b. correlation of a and b returns is 0.65. historical return year investment a investment b 2014 13.63% 19.12% 2015 1.35% 9.54% 2016 11.93% 7.01% 2017 21.78% 32.70% 2018 -4.42% -0.14% 2019 31.46% 39.12% calculate: average return for investment a average return for investment b average portfolio return standard deviation for investment a standard deviation for investment b standard deviation of portfolio