Finding the Fourth Proportional to 20,687.98, 31,032.27 and 5,105.61

Step by Step Solution

1. Step 1: Write the proportion equation
   20,687.98 : 31,032.27 = 5,105.61 : x
2. Step 2: Convert to fraction form
   20,687.98/31,032.27 = 5,105.61/x
3. Step 3: Cross multiply
   20,687.98x = 31,032.27 × 5,105.61
4. Step 4: Simplify right side
   20,687.98x = 158,438,512.87
5. Step 5: Solve for x
   x = 158,438,512.87/20,687.98
6. Step 6: Final answer
   x = 7,658.48