Finding the Fourth Proportional to 120,399.38, 166,152.39 and 72,643.50

Step by Step Solution

1. Step 1: Write the proportion equation
   120,399.38 : 166,152.39 = 72,643.50 : x
2. Step 2: Convert to fraction form
   120,399.38/166,152.39 = 72,643.50/x
3. Step 3: Cross multiply
   120,399.38x = 166,152.39 × 72,643.50
4. Step 4: Simplify right side
   120,399.38x = 12,069,891,142.97
5. Step 5: Solve for x
   x = 12,069,891,142.97/120,399.38
6. Step 6: Final answer
   x = 100,248.78