Assume the following: you have $10,000 to invest; the current spot rate of British pounds is $1.800; the 90- day forward rate of the pound is $1.780; the annual interest rate in the U.S. is 4%; the annual interest rate in the U.K. is 6%.

Given the spot rate, the forward rate, and the U.S. interest rate, what is the equilibrium U.K. interest rate?