Finding the Fourth Proportional to 21,336.48, 31,942.71 and 12,424.61

Step by Step Solution

1. Step 1: Write the proportion equation
   21,336.48 : 31,942.71 = 12,424.61 : x
2. Step 2: Convert to fraction form
   21,336.48/31,942.71 = 12,424.61/x
3. Step 3: Cross multiply
   21,336.48x = 31,942.71 × 12,424.61
4. Step 4: Simplify right side
   21,336.48x = 396,875,554.38
5. Step 5: Solve for x
   x = 396,875,554.38/21,336.48
6. Step 6: Final answer
   x = 18,600.80