Please help with this question

There is a $30,000 portfolio that consists of Stocks X, Y, and Z? You invest equally in the three stocks. State of Economy Probability of state of economy Rate of Return if State Occurs X Y Z Boom 0.15 11% -9% 7% Normal 0.65 8% 7% -3% Weak 0.1 5% 10% 4% Bust ??? -5% 14% 9% a. (1 points) What is the expected return of the portfolio? b. (1 points) What is the standard deviation of the portfolio? c. (2 points) Using risks and returns of the above portfolio, demonstrate how diversification helps in reducing the portfolio risk. Please use risks and returns of the securities versus the portfolio to answer this question. For the toolbar, press ALT+F10 (PC) or ALT+FN+F10 (Mac). BIUS Paragraph Arial 14px V A v V TX