The correlation between Cisco Systems, Inc's (Ticker: CSCO) returns and Bank of America Corporation's (Ticker: BAC) returns is 0.4057469. Cisco Systems, Inc has a standard deviation of returns of 7.61735 percent while Bank of America Corporation has a standard deviation of returns of 10.26397 percent. Calculate the standard deviation of returns for a portfolio consisting of 71 percent Cisco Systems, Inc stock and 29 percent Bank of America Corporation stock.