Margaret is retired and a widow. Her husband left her a generous estate. As a result, Margaret likes to assist family and friends in time of financial hardship.

During the year, she made an interest free loan to her nephew, Ray, who is attending a university and studying engineering.

She loaned Ray $$85,000$ to help pay for tuition, fees, and books.

Ray's only source of income is a part$-$time job at a grocery store.

The Federal rate is currently at $4\%.$

What would be Ray's investment interest expense be on the above?