Explanation

Let's find the unknown value x using the proportion x : 5 :: 6 : 15.

We can set up the proportion as x/5 = 6/15.

Step 1: Cross-multiply

15x = 6 * 5

Step 2: Simplify

15x = 30

Step 3: Solve for x

x = 30 / 15

x = 2