A homeowner took out a $25-$year fixed$-$rate mortgage of $$110,000.$ The mortgage was taken out $13$ years ago at a rate of $7\mathrm{.}85$ percent.

If the homeowner refinances, the charges will be $$1,900.$ What is the highest interest rate at which it would be beneficial to refinance

the mortgage?

Note: Do not round intermediate calculations. Enter your answer as a percent rounded to $2$ decimal places.

APR