Finding the Third Proportional to 321,661 and 687,494

Step by Step Solution

1. Step 1: Write the proportion equation
   321,661 : 687,494 = 687,494 : x
2. Step 2: Convert to fraction form
   321,661/687,494 = 687,494/x
3. Step 3: Cross multiply
   321,661x = 687,494 × 687,494
4. Step 4: Simplify right side
   321,661x = 472,648,000,036
5. Step 5: Solve for x
   x = 472,648,000,036/321,661
6. Step 6: Final answer
   x = 1,469,397.91