Finding the Fourth Proportional to 139,517.52, 209,046.24 and 80,402.88

Step by Step Solution

1. Step 1: Write the proportion equation
   139,517.52 : 209,046.24 = 80,402.88 : x
2. Step 2: Convert to fraction form
   139,517.52/209,046.24 = 80,402.88/x
3. Step 3: Cross multiply
   139,517.52x = 209,046.24 × 80,402.88
4. Step 4: Simplify right side
   139,517.52x = 16,807,919,749.17
5. Step 5: Solve for x
   x = 16,807,919,749.17/139,517.52
6. Step 6: Final answer
   x = 120,471.75