Finding the Fourth Proportional to 21,105.86, 31,666.38 and 9,871.24

Step by Step Solution

1. Step 1: Write the proportion equation
   21,105.86 : 31,666.38 = 9,871.24 : x
2. Step 2: Convert to fraction form
   21,105.86/31,666.38 = 9,871.24/x
3. Step 3: Cross multiply
   21,105.86x = 31,666.38 × 9,871.24
4. Step 4: Simplify right side
   21,105.86x = 312,586,436.91
5. Step 5: Solve for x
   x = 312,586,436.91/21,105.86
6. Step 6: Final answer
   x = 14,810.41