In the proportion 6 : x :: 9 : 12, the value of x is?

In the proportion 6 : x :: 9 : 12, the value of x is?

Explanation

Given the proportion:

6 : x :: 9 : 12

We can write it as:

6/x = 9/12

Cross-multiplying:

6 × 12 = 9 × x

72 = 9x

x = 72/9

x = 8