in this formula i am calculating and increase of 25 cents per full percent increase in a range of 110%-124%, but when i get to 120% percent this formula becomes inaccurate? what did i do wrong? the formula starts at 4.00$ and adds .25 per/percent.

(IF(E10<1.1,0,4+INT(MOD(E10*10,1)*10)*0.25))