Finding the Fourth Proportional to 81,105.78, 112,002.98 and 76,688.04

Step by Step Solution

1. Step 1: Write the proportion equation
   81,105.78 : 112,002.98 = 76,688.04 : x
2. Step 2: Convert to fraction form
   81,105.78/112,002.98 = 76,688.04/x
3. Step 3: Cross multiply
   81,105.78x = 112,002.98 × 76,688.04
4. Step 4: Simplify right side
   81,105.78x = 8,589,288,626.92
5. Step 5: Solve for x
   x = 8,589,288,626.92/81,105.78
6. Step 6: Final answer
   x = 105,902.30