A ratio fo 7 to 4 is the same as 12 to ?
there is no comon factor to see... 7 is not a multiple of 12.
so set up the equation:
7 12
---- = ------
4 x
Now cross multiply:
7x = 12*4
7x = 48
x = 48/7 = 6.857
multiply 4 by 6.857 to get 27.42
x = 27
so 7/4 as 12/27