Finding the Fourth Proportional to 12,445.92, 18,648.72 and 8,287.20

Step by Step Solution

1. Step 1: Write the proportion equation
   12,445.92 : 18,648.72 = 8,287.20 : x
2. Step 2: Convert to fraction form
   12,445.92/18,648.72 = 8,287.20/x
3. Step 3: Cross multiply
   12,445.92x = 18,648.72 × 8,287.20
4. Step 4: Simplify right side
   12,445.92x = 154,545,672.38
5. Step 5: Solve for x
   x = 154,545,672.38/12,445.92
6. Step 6: Final answer
   x = 12,417.38