Finding the Third Proportional to 312,498 and 647,149.50

Step by Step Solution

1. Step 1: Write the proportion equation
   312,498 : 647,149.50 = 647,149.50 : x
2. Step 2: Convert to fraction form
   312,498/647,149.50 = 647,149.50/x
3. Step 3: Cross multiply
   312,498x = 647,149.50 × 647,149.50
4. Step 4: Simplify right side
   312,498x = 418,802,475,350.25
5. Step 5: Solve for x
   x = 418,802,475,350.25/312,498
6. Step 6: Final answer
   x = 1,340,176.50