2. The followings are weekly stock returns of Walmart (Beta=0.47) and nVidia (Beta=2.74) in the past four weeks. (Hint: Do we need to correct for selection bias?]|| Week of Nov. 12 Nov. 5 Oct. 29 Oct.22 Walmart 3.60% 7.46% -4.16% -2.43% nVidia 11.99% -5.05% 8.30% 6.39% (1) Find the expected return on both companies' common stocks using the four weekly returns. (2) Find the standard deviation of both companies' weekly stock returns. (3) The coviance between the two companies is 0.0023. Fill out the following table using answers to (1) and (2)). Portfolio Weights: Portfolio Weights: Portfolio Portfolio Standard Portfolio Walmart nVidia Expected Return Deviation Beta 100% 0% 90% 10% 80% 20% 70% 30% 60% 40% 50% 50% 40% 60% 30% 70% 20% 80% 10% 90% 0% 100% (4) Plot "Portfolio Expected Return" and "Portfolio Standard Deviation" in (4) and mark the