Finding the Fourth Proportional to 12,139.52, 18,196.31 and 8,666.24

Step by Step Solution

1. Step 1: Write the proportion equation
   12,139.52 : 18,196.31 = 8,666.24 : x
2. Step 2: Convert to fraction form
   12,139.52/18,196.31 = 8,666.24/x
3. Step 3: Cross multiply
   12,139.52x = 18,196.31 × 8,666.24
4. Step 4: Simplify right side
   12,139.52x = 157,693,520.26
5. Step 5: Solve for x
   x = 157,693,520.26/12,139.52
6. Step 6: Final answer
   x = 12,990.10