Finding the Fourth Proportional to 120,554.88, 166,332.78 and 72,137.31

Step by Step Solution

1. Step 1: Write the proportion equation
   120,554.88 : 166,332.78 = 72,137.31 : x
2. Step 2: Convert to fraction form
   120,554.88/166,332.78 = 72,137.31/x
3. Step 3: Cross multiply
   120,554.88x = 166,332.78 × 72,137.31
4. Step 4: Simplify right side
   120,554.88x = 11,998,799,314.02
5. Step 5: Solve for x
   x = 11,998,799,314.02/120,554.88
6. Step 6: Final answer
   x = 99,529.77