Finding the Third Proportional to 331,406 and 518,435.50

Step by Step Solution

1. Step 1: Write the proportion equation
   331,406 : 518,435.50 = 518,435.50 : x
2. Step 2: Convert to fraction form
   331,406/518,435.50 = 518,435.50/x
3. Step 3: Cross multiply
   331,406x = 518,435.50 × 518,435.50
4. Step 4: Simplify right side
   331,406x = 268,775,367,660.25
5. Step 5: Solve for x
   x = 268,775,367,660.25/331,406
6. Step 6: Final answer
   x = 811,015.39