Finding the Fourth Proportional to 10,872.72, 15,004.80 and 9,385.20

Step by Step Solution

1. Step 1: Write the proportion equation
   10,872.72 : 15,004.80 = 9,385.20 : x
2. Step 2: Convert to fraction form
   10,872.72/15,004.80 = 9,385.20/x
3. Step 3: Cross multiply
   10,872.72x = 15,004.80 × 9,385.20
4. Step 4: Simplify right side
   10,872.72x = 140,823,048.96
5. Step 5: Solve for x
   x = 140,823,048.96/10,872.72
6. Step 6: Final answer
   x = 12,951.96