9 | |
4 |
= |
30 |
x |
If 2 proportions are equal:
we can cross multiply to get:
Numerator 1 Denominator 1
=
Numerator 2 Denominator 2 Numerator 1 * Denominator 2 = Denominator 1 * Numerator 2
Denominator 2 = | Denominator 1 * Numerator 2 |
Numerator 1 |
x = | 4 * 30 |
9 |
x = | 120 |
9 |