Finding the Third Proportional to 8,540 and 12,685.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,540 : 12,685.50 = 12,685.50 : x
2. Step 2: Convert to fraction form
   8,540/12,685.50 = 12,685.50/x
3. Step 3: Cross multiply
   8,540x = 12,685.50 × 12,685.50
4. Step 4: Simplify right side
   8,540x = 160,921,910.25
5. Step 5: Solve for x
   x = 160,921,910.25/8,540
6. Step 6: Final answer
   x = 18,843.32