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 Walmart nVidia (1) Find the expected returns on both companies' common stocks using the four weekly return:s 10 points) (2) Find the standard deviations of both companies' weekly stock returns. (10 points) (3) Find the correlation coefficient between the two companies' common stocks. [CH11 Slide 26] 10 points) Nov. 12 -3.60% -11.99% Nov. 5 -7.46% -20.05% Oct. 29 4.16% 4.30% Oct.22 2.43% 8.39%