3/18 =4x/7
solve the proportion by using cross products.

3/18 = 4x/7

 3/18 reduces to 1/6

 multiply both sides to get 4x = 1/6*7

1/6* 7 = 1/6*7/1=7/6

4x = 7/6

now divide 7/6 by 4 to get x

x = 7/6 / 4/1 = 7/6 * 1/4 = 7/24

x = 7/24

828. all there is to it!

here, if you ever need with rounding (or other forms of arithmetic/math) again, use this:

thats the rounding one, but if you just click the top left, it shows you all the calculators you may need!