I want the step to calculate it, the ans is 0.0115

Suppose a stock fund earns a return of 19% with a standard deviation of 5%. The risk-free asset offers a return of 2.72%. What is the standard deviation of your portfolio return if you invest 23% of your savings in the stock fund and the rest in the risk-free asset? Report your answer in decimal form (not in percentage) showing 4 digit precision