Finding the Fourth Proportional to 12,857.59, 17,745.38 and 8,142.31

Step by Step Solution

1. Step 1: Write the proportion equation
   12,857.59 : 17,745.38 = 8,142.31 : x
2. Step 2: Convert to fraction form
   12,857.59/17,745.38 = 8,142.31/x
3. Step 3: Cross multiply
   12,857.59x = 17,745.38 × 8,142.31
4. Step 4: Simplify right side
   12,857.59x = 144,488,385.03
5. Step 5: Solve for x
   x = 144,488,385.03/12,857.59
6. Step 6: Final answer
   x = 11,237.59