Your eccentric Aunt Claudia has left you $50,000 in BP shares plus $50,000 cash. Unfortunately, her will requires that the BP stock not be sold for one year and the $50,000 cash must be entirely invested in one of the stocks shown below. a. Calculate the portfolio variance for seven different portfolios. Note: Use decimals, not percents, in your calculations. Do not round intermediate calculations. Enter your answers as a decimal rounded to 5 places. b. What is the safest attainable portfolio under these restrictions? Complete this question by entering your answers in the tabs below. Calculate the portfolio variance for seven different portfolios. Note: Use decimals, not percents, in your calculations. Do not round intermediate calculations. Enter your answers as a decimal rounded to 5 places