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?