A local bank is running the following advertisement in the$$ newspaper: "For just $$$$4$ comma $000$ we will pay you $$$$200$forever$!"$ The fine print in the ad says that for a $$$$4$ comma $000$deposit$,$ the bank will pay $$$$200$ every year in$$ perpetuity, starting one year after the deposit is made. What interest rate is the bank advertising$($what is the IRR of this$$ investment$)?$