Finding the Fourth Proportional to 12,162.72, 16,764.36 and 9,640.38

Step by Step Solution

1. Step 1: Write the proportion equation
   12,162.72 : 16,764.36 = 9,640.38 : x
2. Step 2: Convert to fraction form
   12,162.72/16,764.36 = 9,640.38/x
3. Step 3: Cross multiply
   12,162.72x = 16,764.36 × 9,640.38
4. Step 4: Simplify right side
   12,162.72x = 161,614,800.86
5. Step 5: Solve for x
   x = 161,614,800.86/12,162.72
6. Step 6: Final answer
   x = 13,287.72