II am having difficulties setting up the formulas could you please show the work especially for the standard deviation.

Carol is considering investing in a company's stock and is aware that the return on that investment is particularly sensitive to how the economy is performing. Her analysis suggests that four states of the economy can affect the return on the investment. Probability 0.3 Return 25.00% Boom Good 0.2 15.00% Level 0.2 10.00% Slump 0.3 -5.00% Use the table of returns and probabilities above to determine the expected return on Carol's investment? (Round answer to 3 decimal places, e.g. 0.076.) Expected return Use the table of returns and probabilities above to determine the standard deviation of the return on Carol's investment? (Round answer to 5 decimal places, e.g. 0.07680.) Standard deviation