Finding the Fourth Proportional to 21,648.72, 29,864.23 and 13,148.58

Step by Step Solution

1. Step 1: Write the proportion equation
   21,648.72 : 29,864.23 = 13,148.58 : x
2. Step 2: Convert to fraction form
   21,648.72/29,864.23 = 13,148.58/x
3. Step 3: Cross multiply
   21,648.72x = 29,864.23 × 13,148.58
4. Step 4: Simplify right side
   21,648.72x = 392,672,184.42
5. Step 5: Solve for x
   x = 392,672,184.42/21,648.72
6. Step 6: Final answer
   x = 18,138.36