Finding the Fourth Proportional to 21,078.38, 31,630.22 and 8,425.87

Step by Step Solution

1. Step 1: Write the proportion equation
   21,078.38 : 31,630.22 = 8,425.87 : x
2. Step 2: Convert to fraction form
   21,078.38/31,630.22 = 8,425.87/x
3. Step 3: Cross multiply
   21,078.38x = 31,630.22 × 8,425.87
4. Step 4: Simplify right side
   21,078.38x = 266,512,100.73
5. Step 5: Solve for x
   x = 266,512,100.73/21,078.38
6. Step 6: Final answer
   x = 12,643.86