need the following answered in detail on Excel

i found out STM has a standard deviation of 18, is it the riskier out of the three stocks

Exercises 1. Consider the following information on computer peripheral companies STMicroelectronics STM, Synaptics SYNA and SuperMicro SMCI State of Economy Recession Normal Boom Probability of State of Economy 25.0% 300% 55.0% Rate of Return State Occurs STM SYNA SMCI -10.55% -8.35% -1.00% 14.22% 10.85% 15.90% 33.65% 13,60% 38.50% The market risk premium is 8% and the risk-free rate is 4.50%. Determine the expected return and standard deviation for each stock. Which stock has the most systematic risk? Which one has the most unsystematic risk? Which stock is riskier overall? (75 POINTS) 2. ZOOM Video Communications ZM stock currently sells for $402.20 per share. ZM just paid a dividend of $4.25. If the required rate of return on ZM stock or similar video communication companies is 6.95%, which should be the constant dividend growth rate? (50 POINTS)