Your eccentric Aunt Claudia has left you $50,000 in BP shares plus $50,000cash. Unfortunately, her will requires that the BP stock 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. (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? Your eccentric Aunt Claudia has left you $50,000 in BP shares plus $50,000cash. Unfortunately, her will requires that the BP stock 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. (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