Hmm... I understand if you are not a mathematician, but your question does need to be a bit more specific. Are 1.25, 14.80, 7.72 the only data you need this to work for? Can you substitute these three for different values? What about negative numbers? More than three?
Given an arbitrary finite list of numbers , the following two formulas will guarantee a decimal part smaller than .25:
(add up the numbers each rounded to the nearest integer)
(sine is always between -1 and 1, so dividing by 4 gets you a number between -.25 and .25)
I cannot see the first possible use of these formulas in the "real" world, so I perhaps am misunderstanding your question.