if x/4=7/2 what is x
$${\frac{{\mathtt{x}}}{{\mathtt{4}}}}$$ = $${\frac{{\mathtt{7}}}{{\mathtt{2}}}}$$
This is a proportion, so you can cross-multiply:
2 * x = 4 * 7
2x = 28
Divide by 2:
x = 14