Finding the Fourth Proportional to 99,105.69, 136,721.21 and 58,821.15

Step by Step Solution

1. Step 1: Write the proportion equation
   99,105.69 : 136,721.21 = 58,821.15 : x
2. Step 2: Convert to fraction form
   99,105.69/136,721.21 = 58,821.15/x
3. Step 3: Cross multiply
   99,105.69x = 136,721.21 × 58,821.15
4. Step 4: Simplify right side
   99,105.69x = 8,042,098,507.49
5. Step 5: Solve for x
   x = 8,042,098,507.49/99,105.69
6. Step 6: Final answer
   x = 81,146.69