Finding the Fourth Proportional to 272,789.18, 408,921.34 and 139,732.10

Step by Step Solution

1. Step 1: Write the proportion equation
   272,789.18 : 408,921.34 = 139,732.10 : x
2. Step 2: Convert to fraction form
   272,789.18/408,921.34 = 139,732.10/x
3. Step 3: Cross multiply
   272,789.18x = 408,921.34 × 139,732.10
4. Step 4: Simplify right side
   272,789.18x = 57,139,437,573.01
5. Step 5: Solve for x
   x = 57,139,437,573.01/272,789.18
6. Step 6: Final answer
   x = 209,463.72