Finding the Fourth Proportional to 8,641.11, 12,887.25 and 8,485.59

Step by Step Solution

1. Step 1: Write the proportion equation
   8,641.11 : 12,887.25 = 8,485.59 : x
2. Step 2: Convert to fraction form
   8,641.11/12,887.25 = 8,485.59/x
3. Step 3: Cross multiply
   8,641.11x = 12,887.25 × 8,485.59
4. Step 4: Simplify right side
   8,641.11x = 109,355,919.73
5. Step 5: Solve for x
   x = 109,355,919.73/8,641.11
6. Step 6: Final answer
   x = 12,655.31