Finding the Fourth Proportional to 89,819.30, 134,498.55 and 85,672.10

Step by Step Solution

1. Step 1: Write the proportion equation
   89,819.30 : 134,498.55 = 85,672.10 : x
2. Step 2: Convert to fraction form
   89,819.30/134,498.55 = 85,672.10/x
3. Step 3: Cross multiply
   89,819.30x = 134,498.55 × 85,672.10
4. Step 4: Simplify right side
   89,819.30x = 11,522,773,225.46
5. Step 5: Solve for x
   x = 11,522,773,225.46/89,819.30
6. Step 6: Final answer
   x = 128,288.39