Finding the Fourth Proportional to 12,359.88, 18,429.57 and 10,986.12

Step by Step Solution

1. Step 1: Write the proportion equation
   12,359.88 : 18,429.57 = 10,986.12 : x
2. Step 2: Convert to fraction form
   12,359.88/18,429.57 = 10,986.12/x
3. Step 3: Cross multiply
   12,359.88x = 18,429.57 × 10,986.12
4. Step 4: Simplify right side
   12,359.88x = 202,469,467.57
5. Step 5: Solve for x
   x = 202,469,467.57/12,359.88
6. Step 6: Final answer
   x = 16,381.18