Finding the Fourth Proportional to 72,105.98, 99,505.67 and 39,840.50

Step by Step Solution

1. Step 1: Write the proportion equation
   72,105.98 : 99,505.67 = 39,840.50 : x
2. Step 2: Convert to fraction form
   72,105.98/99,505.67 = 39,840.50/x
3. Step 3: Cross multiply
   72,105.98x = 99,505.67 × 39,840.50
4. Step 4: Simplify right side
   72,105.98x = 3,964,355,645.64
5. Step 5: Solve for x
   x = 3,964,355,645.64/72,105.98
6. Step 6: Final answer
   x = 54,979.57