Finding the Fourth Proportional to 139,520.52, 209,050.74 and 80,405.88

Step by Step Solution

1. Step 1: Write the proportion equation
   139,520.52 : 209,050.74 = 80,405.88 : x
2. Step 2: Convert to fraction form
   139,520.52/209,050.74 = 80,405.88/x
3. Step 3: Cross multiply
   139,520.52x = 209,050.74 × 80,405.88
4. Step 4: Simplify right side
   139,520.52x = 16,808,908,714.35
5. Step 5: Solve for x
   x = 16,808,908,714.35/139,520.52
6. Step 6: Final answer
   x = 120,476.25