Finding the Fourth Proportional to 21,456.52, 29,613.54 and 13,072.48

Step by Step Solution

1. Step 1: Write the proportion equation
   21,456.52 : 29,613.54 = 13,072.48 : x
2. Step 2: Convert to fraction form
   21,456.52/29,613.54 = 13,072.48/x
3. Step 3: Cross multiply
   21,456.52x = 29,613.54 × 13,072.48
4. Step 4: Simplify right side
   21,456.52x = 387,122,409.38
5. Step 5: Solve for x
   x = 387,122,409.38/21,456.52
6. Step 6: Final answer
   x = 18,042.18