Finding the Fourth Proportional to 99,910.20, 149,767.86 and 39,920.78

Step by Step Solution

1. Step 1: Write the proportion equation
   99,910.20 : 149,767.86 = 39,920.78 : x
2. Step 2: Convert to fraction form
   99,910.20/149,767.86 = 39,920.78/x
3. Step 3: Cross multiply
   99,910.20x = 149,767.86 × 39,920.78
4. Step 4: Simplify right side
   99,910.20x = 5,978,849,790.13
5. Step 5: Solve for x
   x = 5,978,849,790.13/99,910.20
6. Step 6: Final answer
   x = 59,842.24