| 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 |