Finding the Fourth Proportional to 12,391.31, 17,114.20 and 8,161.29

Step by Step Solution

1. Step 1: Write the proportion equation
   12,391.31 : 17,114.20 = 8,161.29 : x
2. Step 2: Convert to fraction form
   12,391.31/17,114.20 = 8,161.29/x
3. Step 3: Cross multiply
   12,391.31x = 17,114.20 × 8,161.29
4. Step 4: Simplify right side
   12,391.31x = 139,673,949.32
5. Step 5: Solve for x
   x = 139,673,949.32/12,391.31
6. Step 6: Final answer
   x = 11,271.93