Finding the Fourth Proportional to 272,436.56, 408,902.04 and 139,408.72

Step by Step Solution

1. Step 1: Write the proportion equation
   272,436.56 : 408,902.04 = 139,408.72 : x
2. Step 2: Convert to fraction form
   272,436.56/408,902.04 = 139,408.72/x
3. Step 3: Cross multiply
   272,436.56x = 408,902.04 × 139,408.72
4. Step 4: Simplify right side
   272,436.56x = 57,004,510,001.79
5. Step 5: Solve for x
   x = 57,004,510,001.79/272,436.56
6. Step 6: Final answer
   x = 209,239.57