please show steps thanks im struggling with my calcualtions

You have a portfolio which is comprised of 30 percent of stock A and 70 percent of stock B. What is the portfolio standard deviation? State of the Economy Boom Normal Recession Probability 3ex: 70% .15 20.00 14.00 0.7511.00 9.80 0.10 (23.00) (5.00) 6.82 percent 5 56 percent 6.06 percent 400 percent 747 percent