Finding the Fourth Proportional to 11,116.86, 16,680.15 and 8,158.20

Step by Step Solution

1. Step 1: Write the proportion equation
   11,116.86 : 16,680.15 = 8,158.20 : x
2. Step 2: Convert to fraction form
   11,116.86/16,680.15 = 8,158.20/x
3. Step 3: Cross multiply
   11,116.86x = 16,680.15 × 8,158.20
4. Step 4: Simplify right side
   11,116.86x = 136,079,999.73
5. Step 5: Solve for x
   x = 136,079,999.73/11,116.86
6. Step 6: Final answer
   x = 12,240.87