Finding the Fourth Proportional to 105,872.36, 146,104.12 and 58,128.78

Step by Step Solution

1. Step 1: Write the proportion equation
   105,872.36 : 146,104.12 = 58,128.78 : x
2. Step 2: Convert to fraction form
   105,872.36/146,104.12 = 58,128.78/x
3. Step 3: Cross multiply
   105,872.36x = 146,104.12 × 58,128.78
4. Step 4: Simplify right side
   105,872.36x = 8,492,854,248.57
5. Step 5: Solve for x
   x = 8,492,854,248.57/105,872.36
6. Step 6: Final answer
   x = 80,217.86