Finding the Fourth Proportional to 13,143.52, 18,139.72 and 8,676.57

Step by Step Solution

1. Step 1: Write the proportion equation
   13,143.52 : 18,139.72 = 8,676.57 : x
2. Step 2: Convert to fraction form
   13,143.52/18,139.72 = 8,676.57/x
3. Step 3: Cross multiply
   13,143.52x = 18,139.72 × 8,676.57
4. Step 4: Simplify right side
   13,143.52x = 157,390,535.33
5. Step 5: Solve for x
   x = 157,390,535.33/13,143.52
6. Step 6: Final answer
   x = 11,974.77