Finding the Third Proportional to 425,747.25 and 640,399.50

Step by Step Solution

1. Step 1: Write the proportion equation
   425,747.25 : 640,399.50 = 640,399.50 : x
2. Step 2: Convert to fraction form
   425,747.25/640,399.50 = 640,399.50/x
3. Step 3: Cross multiply
   425,747.25x = 640,399.50 × 640,399.50
4. Step 4: Simplify right side
   425,747.25x = 410,111,519,600.25
5. Step 5: Solve for x
   x = 410,111,519,600.25/425,747.25
6. Step 6: Final answer
   x = 963,274.62