Net Present Cost. New Hospice is building an extension. They can use single-pane glass windows that cost $ 1 00 each, or they can buy double-pane windows that cost

$150 each. The windows should last 20 years before they have to be replaced. The hospice expects that heating costs will be lower by $5 per year for each double-pane window they buy. The hospice can borrow or invest money at 1 percent. Which type of window should they buy? What would your answer be if the interest rate was 6 percent? Why did changing the interest rate change the answer?