Security	Face Value	Market Value	Term (in Years)	Annual Coupon	Yield to Maturity
US Treasury Bill	$20,000	$19,192	1	0%
Corporate Bond (Aa Rating)	$67,500	$60,359.20	8	10%	12.14%
Corporate Bond (B Rating)	$112,500	$89,968.9	10	12%	16.17%
Corporate Bond (Baa Rating)	$37,500	$39,753.2	5	15%	13.28%

A portfolio consists of the given securities and also has cash of $7,500.

Using Excel Solver, show how much would need to be invested in each instrument to obtain a portfolio Macaulay duration of 3.25 years.

There are the following constraints.

1) The total investment should not change.

2) The same amount needs to be held in cash

3) A total of $100,000 market value needs to be invested in the T Bill and $20,000 in the Aa Bond.

4) Yield is maximized.