Finding the Fourth Proportional to 12,921.56, 17,831.76 and 7,256.31

Step by Step Solution

1. Step 1: Write the proportion equation
   12,921.56 : 17,831.76 = 7,256.31 : x
2. Step 2: Convert to fraction form
   12,921.56/17,831.76 = 7,256.31/x
3. Step 3: Cross multiply
   12,921.56x = 17,831.76 × 7,256.31
4. Step 4: Simplify right side
   12,921.56x = 129,392,827.13
5. Step 5: Solve for x
   x = 129,392,827.13/12,921.56
6. Step 6: Final answer
   x = 10,013.71