Finding the Fourth Proportional to 21,258.18, 31,843.49 and 12,471.89

Step by Step Solution

1. Step 1: Write the proportion equation
   21,258.18 : 31,843.49 = 12,471.89 : x
2. Step 2: Convert to fraction form
   21,258.18/31,843.49 = 12,471.89/x
3. Step 3: Cross multiply
   21,258.18x = 31,843.49 × 12,471.89
4. Step 4: Simplify right side
   21,258.18x = 397,148,282.92
5. Step 5: Solve for x
   x = 397,148,282.92/21,258.18
6. Step 6: Final answer
   x = 18,682.14