Finding the Third Proportional to 8,558 and 12,540

Step by Step Solution

1. Step 1: Write the proportion equation
   8,558 : 12,540 = 12,540 : x
2. Step 2: Convert to fraction form
   8,558/12,540 = 12,540/x
3. Step 3: Cross multiply
   8,558x = 12,540 × 12,540
4. Step 4: Simplify right side
   8,558x = 157,251,600
5. Step 5: Solve for x
   x = 157,251,600/8,558
6. Step 6: Final answer
   x = 18,374.81