10.9. Calculating returns and variability For the problem set, use your financial calculator. For your Excel homework, use Excel functions. Here, we don't have values of Stock Y, so we leave it as it is given by default. The 'sample' variance is the squared of the 'sample' standard deviation. Sample Variance = Sample St. Dev v2=0.13412= 7. Calculating Returns and Variability Using the following returns, calculate the arithmetic average returns, the variances, and the standard deviations for X and Y