In​ 1975, interest rates were 7.85 % and the rate of inflation was 12.3 % in the United States. What was the real interest rate in​ 1975? How would the purchasing power of your savings have changed over the​ year? ​(Note: Be careful not to round any intermediate steps less than six decimal​ places.) What was the real interest rate in​ 1975?   Real rate of interest in 1975 was nothing​%. ​(Round to two decimal​ places.)