Finding the Third Proportional to 256,441 and 398,104.50

Step by Step Solution

1. Step 1: Write the proportion equation
   256,441 : 398,104.50 = 398,104.50 : x
2. Step 2: Convert to fraction form
   256,441/398,104.50 = 398,104.50/x
3. Step 3: Cross multiply
   256,441x = 398,104.50 × 398,104.50
4. Step 4: Simplify right side
   256,441x = 158,487,192,920.25
5. Step 5: Solve for x
   x = 158,487,192,920.25/256,441
6. Step 6: Final answer
   x = 618,025.95