Finding the Third Proportional to 8,439 and 12,331.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,439 : 12,331.50 = 12,331.50 : x
2. Step 2: Convert to fraction form
   8,439/12,331.50 = 12,331.50/x
3. Step 3: Cross multiply
   8,439x = 12,331.50 × 12,331.50
4. Step 4: Simplify right side
   8,439x = 152,065,892.25
5. Step 5: Solve for x
   x = 152,065,892.25/8,439
6. Step 6: Final answer
   x = 18,019.42