Finding the Fourth Proportional to 8,557.86, 12,857.34 and 8,085.81

Step by Step Solution

1. Step 1: Write the proportion equation
   8,557.86 : 12,857.34 = 8,085.81 : x
2. Step 2: Convert to fraction form
   8,557.86/12,857.34 = 8,085.81/x
3. Step 3: Cross multiply
   8,557.86x = 12,857.34 × 8,085.81
4. Step 4: Simplify right side
   8,557.86x = 103,962,008.35
5. Step 5: Solve for x
   x = 103,962,008.35/8,557.86
6. Step 6: Final answer
   x = 12,148.13