Finding the Third Proportional to 129,399.75 and 282,856.50

Step by Step Solution

1. Step 1: Write the proportion equation
   129,399.75 : 282,856.50 = 282,856.50 : x
2. Step 2: Convert to fraction form
   129,399.75/282,856.50 = 282,856.50/x
3. Step 3: Cross multiply
   129,399.75x = 282,856.50 × 282,856.50
4. Step 4: Simplify right side
   129,399.75x = 80,007,799,592.25
5. Step 5: Solve for x
   x = 80,007,799,592.25/129,399.75
6. Step 6: Final answer
   x = 618,299.49