Finding the Fourth Proportional to 120,811.27, 166,714.15 and 72,439.90

Step by Step Solution

1. Step 1: Write the proportion equation
   120,811.27 : 166,714.15 = 72,439.90 : x
2. Step 2: Convert to fraction form
   120,811.27/166,714.15 = 72,439.90/x
3. Step 3: Cross multiply
   120,811.27x = 166,714.15 × 72,439.90
4. Step 4: Simplify right side
   120,811.27x = 12,076,755,851.59
5. Step 5: Solve for x
   x = 12,076,755,851.59/120,811.27
6. Step 6: Final answer
   x = 99,963.82