Finding the Fourth Proportional to 72,139.71, 99,550.89 and 40,308.87

Step by Step Solution

1. Step 1: Write the proportion equation
   72,139.71 : 99,550.89 = 40,308.87 : x
2. Step 2: Convert to fraction form
   72,139.71/99,550.89 = 40,308.87/x
3. Step 3: Cross multiply
   72,139.71x = 99,550.89 × 40,308.87
4. Step 4: Simplify right side
   72,139.71x = 4,012,783,883.39
5. Step 5: Solve for x
   x = 4,012,783,883.39/72,139.71
6. Step 6: Final answer
   x = 55,625.17