Finding the Third Proportional to 311,356.50 and 680,395.50

Step by Step Solution

1. Step 1: Write the proportion equation
   311,356.50 : 680,395.50 = 680,395.50 : x
2. Step 2: Convert to fraction form
   311,356.50/680,395.50 = 680,395.50/x
3. Step 3: Cross multiply
   311,356.50x = 680,395.50 × 680,395.50
4. Step 4: Simplify right side
   311,356.50x = 462,938,036,420.25
5. Step 5: Solve for x
   x = 462,938,036,420.25/311,356.50
6. Step 6: Final answer
   x = 1,486,842.37