Finding the Fourth Proportional to 12,081.54, 18,112.23 and 8,391

Step by Step Solution

1. Step 1: Write the proportion equation
   12,081.54 : 18,112.23 = 8,391 : x
2. Step 2: Convert to fraction form
   12,081.54/18,112.23 = 8,391/x
3. Step 3: Cross multiply
   12,081.54x = 18,112.23 × 8,391
4. Step 4: Simplify right side
   12,081.54x = 151,979,721.93
5. Step 5: Solve for x
   x = 151,979,721.93/12,081.54
6. Step 6: Final answer
   x = 12,579.50