Finding the Fourth Proportional to 72,288.43, 99,749.20 and 40,020.61

Step by Step Solution

1. Step 1: Write the proportion equation
   72,288.43 : 99,749.20 = 40,020.61 : x
2. Step 2: Convert to fraction form
   72,288.43/99,749.20 = 40,020.61/x
3. Step 3: Cross multiply
   72,288.43x = 99,749.20 × 40,020.61
4. Step 4: Simplify right side
   72,288.43x = 3,992,023,831.01
5. Step 5: Solve for x
   x = 3,992,023,831.01/72,288.43
6. Step 6: Final answer
   x = 55,223.55