Finding the Fourth Proportional to 8,411.29, 12,617.29 and 3,145.78

Step by Step Solution

1. Step 1: Write the proportion equation
   8,411.29 : 12,617.29 = 3,145.78 : x
2. Step 2: Convert to fraction form
   8,411.29/12,617.29 = 3,145.78/x
3. Step 3: Cross multiply
   8,411.29x = 12,617.29 × 3,145.78
4. Step 4: Simplify right side
   8,411.29x = 39,691,147.59
5. Step 5: Solve for x
   x = 39,691,147.59/8,411.29
6. Step 6: Final answer
   x = 4,718.79