Finding the Fourth Proportional to 8,411.86, 12,631.86 and 5,256.64

Step by Step Solution

1. Step 1: Write the proportion equation
   8,411.86 : 12,631.86 = 5,256.64 : x
2. Step 2: Convert to fraction form
   8,411.86/12,631.86 = 5,256.64/x
3. Step 3: Cross multiply
   8,411.86x = 12,631.86 × 5,256.64
4. Step 4: Simplify right side
   8,411.86x = 66,401,140.55
5. Step 5: Solve for x
   x = 66,401,140.55/8,411.86
6. Step 6: Final answer
   x = 7,893.75