General

well the formula is 1 x (4int + luk) x matk/100
well first i figured out that 1 matk would be (4int + luk)/100 and the value you get is the range boost you would recieve with 1 more matk so the answer/(4/.01matk)would give you how much int would equal 1 matk
the (4int X matk/100) gives you the rate of how much each int. is worth by multiplying it by all variables and dividing by the range increase
so prove my equation work ill take an example using the equation i came with (4A +B)/4C
then use the values with the actual equation to show equalvalence

I forgot i can't double post so ill continue

Lets say i hav 623 int. 118 luk and 153 matk
my range would be 3993.3 and adding 1 more matk would make the range 4019.4
to get to 4019.4 with an x increase with int i use the (4A + B)/4C to see the eqivalence and get 4.2647...
so adding that to my equation the new int would be 627.2647... and the reason im keeping decimals is to keep the numbers accurate so i dont get rounding errors and my range is 4019.399964 which is pretty much 4019.4

(equation for 1 matk range increase)/(int rate) .01C is how much each int is worth

((4A+ B)/100)/(4/.01C) = (4A+B)/100/400/C = (4A+B)/1/4/C=(4A+B)/4/C = .25(4A+B)/C = (4A+B)/4C
A=int
B=luk
C=matk

well the int and matk vaires depending on how much you have of each
becausethe more int you hav the more matk affects your range which means its takes a lot of int in order to get the same dmg increase as 1 matk
ex. 600 int 100 luk 100 matk
range is 2500 so 1 more matk would increased it by 25
ex 2. 900 int 100 luk 100 matk
range is 3700 and 1 more matk would increased it by 37 which means 1 matk is worth more int than the previous example