Finding the Fourth Proportional to 139,521.52, 209,052.24 and 80,406.88

Step by Step Solution

1. Step 1: Write the proportion equation
   139,521.52 : 209,052.24 = 80,406.88 : x
2. Step 2: Convert to fraction form
   139,521.52/209,052.24 = 80,406.88/x
3. Step 3: Cross multiply
   139,521.52x = 209,052.24 × 80,406.88
4. Step 4: Simplify right side
   139,521.52x = 16,809,238,375.41
5. Step 5: Solve for x
   x = 16,809,238,375.41/139,521.52
6. Step 6: Final answer
   x = 120,477.75