Obtain the stock prices on BP for the period May 15, 2022 to May 14, 2023. What was the monthly standard deviation of BP stock during that period? What is the annual standard deviation? What was the annual and monthly percentage standard deviations? Do the same thing for the period May 15, 2021 to May 14, 2022. While you can use the excel formulas =sum, and =average, do not use any formulas that directly calculate standard deviation and variance. Post the excel sheet and the calculations.