Finding the Third Proportional to 256,437 and 398,098.50

Step by Step Solution

1. Step 1: Write the proportion equation
   256,437 : 398,098.50 = 398,098.50 : x
2. Step 2: Convert to fraction form
   256,437/398,098.50 = 398,098.50/x
3. Step 3: Cross multiply
   256,437x = 398,098.50 × 398,098.50
4. Step 4: Simplify right side
   256,437x = 158,482,415,702.25
5. Step 5: Solve for x
   x = 158,482,415,702.25/256,437
6. Step 6: Final answer
   x = 618,016.96