Finding the Fourth Proportional to 21,020.72, 29,013.54 and 12,072.92

Step by Step Solution

1. Step 1: Write the proportion equation
   21,020.72 : 29,013.54 = 12,072.92 : x
2. Step 2: Convert to fraction form
   21,020.72/29,013.54 = 12,072.92/x
3. Step 3: Cross multiply
   21,020.72x = 29,013.54 × 12,072.92
4. Step 4: Simplify right side
   21,020.72x = 350,278,147.34
5. Step 5: Solve for x
   x = 350,278,147.34/21,020.72
6. Step 6: Final answer
   x = 16,663.47