Finding the Fourth Proportional to 12,871.47, 17,757.34 and 7,831.65

Step by Step Solution

1. Step 1: Write the proportion equation
   12,871.47 : 17,757.34 = 7,831.65 : x
2. Step 2: Convert to fraction form
   12,871.47/17,757.34 = 7,831.65/x
3. Step 3: Cross multiply
   12,871.47x = 17,757.34 × 7,831.65
4. Step 4: Simplify right side
   12,871.47x = 139,069,183.02
5. Step 5: Solve for x
   x = 139,069,183.02/12,871.47
6. Step 6: Final answer
   x = 10,804.46