Finding the Fourth Proportional to 8,511.30, 12,738.15 and 8,511.30

Step by Step Solution

1. Step 1: Write the proportion equation
   8,511.30 : 12,738.15 = 8,511.30 : x
2. Step 2: Convert to fraction form
   8,511.30/12,738.15 = 8,511.30/x
3. Step 3: Cross multiply
   8,511.30x = 12,738.15 × 8,511.30
4. Step 4: Simplify right side
   8,511.30x = 108,418,216.10
5. Step 5: Solve for x
   x = 108,418,216.10/8,511.30
6. Step 6: Final answer
   x = 12,738.15