so the headline rate is 5.48% on the comparison sites.

interest rates are as follows:

year 1 is 3.5%

year 2 is 4.5%

year 3 is 5.5%

as far as i can see the average interest rate over the 3 years has to therefore be 4.5%. even if you compound the interest it is still ony 4.7% ... so can someone smarter than me explain how they arrive at 5.48% ???????