Finding the Third Proportional to 321,124.50 and 661,689

Step by Step Solution

1. Step 1: Write the proportion equation
   321,124.50 : 661,689 = 661,689 : x
2. Step 2: Convert to fraction form
   321,124.50/661,689 = 661,689/x
3. Step 3: Cross multiply
   321,124.50x = 661,689 × 661,689
4. Step 4: Simplify right side
   321,124.50x = 437,832,332,721
5. Step 5: Solve for x
   x = 437,832,332,721/321,124.50
6. Step 6: Final answer
   x = 1,363,434.84