Finding the Third Proportional to 256,408 and 398,050.50

Step by Step Solution

1. Step 1: Write the proportion equation
   256,408 : 398,050.50 = 398,050.50 : x
2. Step 2: Convert to fraction form
   256,408/398,050.50 = 398,050.50/x
3. Step 3: Cross multiply
   256,408x = 398,050.50 × 398,050.50
4. Step 4: Simplify right side
   256,408x = 158,444,200,550.25
5. Step 5: Solve for x
   x = 158,444,200,550.25/256,408
6. Step 6: Final answer
   x = 617,937.82