Finding the Fourth Proportional to 21,096.48, 31,644.72 and 8,616.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,096.48 : 31,644.72 = 8,616.72 : x
2. Step 2: Convert to fraction form
   21,096.48/31,644.72 = 8,616.72/x
3. Step 3: Cross multiply
   21,096.48x = 31,644.72 × 8,616.72
4. Step 4: Simplify right side
   21,096.48x = 272,673,691.72
5. Step 5: Solve for x
   x = 272,673,691.72/21,096.48
6. Step 6: Final answer
   x = 12,925.08