Grant bought a new lawn tractor on his credit card for $1998. He pays his credit card off in full each month so that he does not incur huge credit card interest on his purchases. This month he was a little short on cash so he paid off the credit card balance using his secured line of credit, which charges him prime (2.75%) plus 1%. If he paid off the line of credit in two equal installments, plus the interest, at 15 days after the purchase and 30 days after the purchase, what was the total amount of interest paid on the purchase of the lawn tractor?