call me names, but please explain this real, real slow because I just don't understand.

If a loan is taken out on $100,000 at 3.2% for 30 years with monthly payments the monthly payment is $432.47   
If the rate is 2% the monthly payment is  $369.62
If the rate is 5.2% the monthly payment is $549.11,  that .032 + .02 = .052

I can't understand why the monthly payment at the increase interest isn't $432.47+$369.62 = $802.09