Finding the Third Proportional to 311,411.25 and 680,980.50

Step by Step Solution

1. Step 1: Write the proportion equation
   311,411.25 : 680,980.50 = 680,980.50 : x
2. Step 2: Convert to fraction form
   311,411.25/680,980.50 = 680,980.50/x
3. Step 3: Cross multiply
   311,411.25x = 680,980.50 × 680,980.50
4. Step 4: Simplify right side
   311,411.25x = 463,734,441,380.25
5. Step 5: Solve for x
   x = 463,734,441,380.25/311,411.25
6. Step 6: Final answer
   x = 1,489,138.37