Finding the Fourth Proportional to 12,072.48, 18,112.36 and 8,139.52

Step by Step Solution

1. Step 1: Write the proportion equation
   12,072.48 : 18,112.36 = 8,139.52 : x
2. Step 2: Convert to fraction form
   12,072.48/18,112.36 = 8,139.52/x
3. Step 3: Cross multiply
   12,072.48x = 18,112.36 × 8,139.52
4. Step 4: Simplify right side
   12,072.48x = 147,425,934.02
5. Step 5: Solve for x
   x = 147,425,934.02/12,072.48
6. Step 6: Final answer
   x = 12,211.74