Finding the Fourth Proportional to 12,078.42, 18,128.57 and 8,382.39

Step by Step Solution

1. Step 1: Write the proportion equation
   12,078.42 : 18,128.57 = 8,382.39 : x
2. Step 2: Convert to fraction form
   12,078.42/18,128.57 = 8,382.39/x
3. Step 3: Cross multiply
   12,078.42x = 18,128.57 × 8,382.39
4. Step 4: Simplify right side
   12,078.42x = 151,960,701.97
5. Step 5: Solve for x
   x = 151,960,701.97/12,078.42
6. Step 6: Final answer
   x = 12,581.17