Finding the Fourth Proportional to 87,719.10, 131,405.85 and 81,498.30

Step by Step Solution

1. Step 1: Write the proportion equation
   87,719.10 : 131,405.85 = 81,498.30 : x
2. Step 2: Convert to fraction form
   87,719.10/131,405.85 = 81,498.30/x
3. Step 3: Cross multiply
   87,719.10x = 131,405.85 × 81,498.30
4. Step 4: Simplify right side
   87,719.10x = 10,709,353,385.06
5. Step 5: Solve for x
   x = 10,709,353,385.06/87,719.10
6. Step 6: Final answer
   x = 122,086.90