Finding the Third Proportional to 128,200.50 and 280,566

Step by Step Solution

1. Step 1: Write the proportion equation
   128,200.50 : 280,566 = 280,566 : x
2. Step 2: Convert to fraction form
   128,200.50/280,566 = 280,566/x
3. Step 3: Cross multiply
   128,200.50x = 280,566 × 280,566
4. Step 4: Simplify right side
   128,200.50x = 78,717,280,356
5. Step 5: Solve for x
   x = 78,717,280,356/128,200.50
6. Step 6: Final answer
   x = 614,016.95