Finding the Fourth Proportional to 12,061.62, 18,120.15 and 8,511.90

Step by Step Solution

1. Step 1: Write the proportion equation
   12,061.62 : 18,120.15 = 8,511.90 : x
2. Step 2: Convert to fraction form
   12,061.62/18,120.15 = 8,511.90/x
3. Step 3: Cross multiply
   12,061.62x = 18,120.15 × 8,511.90
4. Step 4: Simplify right side
   12,061.62x = 154,236,904.79
5. Step 5: Solve for x
   x = 154,236,904.79/12,061.62
6. Step 6: Final answer
   x = 12,787.41