Finding the Fourth Proportional to 424,418.72, 636,691.37 and 140,139.30

Step by Step Solution

1. Step 1: Write the proportion equation
   424,418.72 : 636,691.37 = 140,139.30 : x
2. Step 2: Convert to fraction form
   424,418.72/636,691.37 = 140,139.30/x
3. Step 3: Cross multiply
   424,418.72x = 636,691.37 × 140,139.30
4. Step 4: Simplify right side
   424,418.72x = 89,225,481,666.46
5. Step 5: Solve for x
   x = 89,225,481,666.46/424,418.72
6. Step 6: Final answer
   x = 210,229.85