The formula for amount of interest is the P*R*T. Because the principal is $650 dollars, and the rate is 4.5% for 1 year, the formula so far is 650*0.045*T. The interest is per annum or annual, so the time has to be in terms of years, which in this case is 1 year. This would give you 650*0.045. The answer for that is simply $29.25.
