Finding the Fourth Proportional to 12,086.17, 18,140.19 and 8,390.14

Step by Step Solution

1. Step 1: Write the proportion equation
   12,086.17 : 18,140.19 = 8,390.14 : x
2. Step 2: Convert to fraction form
   12,086.17/18,140.19 = 8,390.14/x
3. Step 3: Cross multiply
   12,086.17x = 18,140.19 × 8,390.14
4. Step 4: Simplify right side
   12,086.17x = 152,198,733.73
5. Step 5: Solve for x
   x = 152,198,733.73/12,086.17
6. Step 6: Final answer
   x = 12,592.80