Finding the Fourth Proportional to 13,311.72, 18,372.42 and 7,725.96

Step by Step Solution

1. Step 1: Write the proportion equation
   13,311.72 : 18,372.42 = 7,725.96 : x
2. Step 2: Convert to fraction form
   13,311.72/18,372.42 = 7,725.96/x
3. Step 3: Cross multiply
   13,311.72x = 18,372.42 × 7,725.96
4. Step 4: Simplify right side
   13,311.72x = 141,944,582.02
5. Step 5: Solve for x
   x = 141,944,582.02/13,311.72
6. Step 6: Final answer
   x = 10,663.13