Finding the Fourth Proportional to 21,124.50, 31,687.20 and 7,983.06

Step by Step Solution

1. Step 1: Write the proportion equation
   21,124.50 : 31,687.20 = 7,983.06 : x
2. Step 2: Convert to fraction form
   21,124.50/31,687.20 = 7,983.06/x
3. Step 3: Cross multiply
   21,124.50x = 31,687.20 × 7,983.06
4. Step 4: Simplify right side
   21,124.50x = 252,960,818.83
5. Step 5: Solve for x
   x = 252,960,818.83/21,124.50
6. Step 6: Final answer
   x = 11,974.76