Finding the Third Proportional to 331,355 and 518,355.50

Step by Step Solution

1. Step 1: Write the proportion equation
   331,355 : 518,355.50 = 518,355.50 : x
2. Step 2: Convert to fraction form
   331,355/518,355.50 = 518,355.50/x
3. Step 3: Cross multiply
   331,355x = 518,355.50 × 518,355.50
4. Step 4: Simplify right side
   331,355x = 268,692,424,380.25
5. Step 5: Solve for x
   x = 268,692,424,380.25/331,355
6. Step 6: Final answer
   x = 810,889.90