Finding the Fourth Proportional to 12,399.12, 17,099.04 and 8,142.69

Step by Step Solution

1. Step 1: Write the proportion equation
   12,399.12 : 17,099.04 = 8,142.69 : x
2. Step 2: Convert to fraction form
   12,399.12/17,099.04 = 8,142.69/x
3. Step 3: Cross multiply
   12,399.12x = 17,099.04 × 8,142.69
4. Step 4: Simplify right side
   12,399.12x = 139,232,182.02
5. Step 5: Solve for x
   x = 139,232,182.02/12,399.12
6. Step 6: Final answer
   x = 11,229.20