Finding the Fourth Proportional to 21,057.72, 29,049.16 and 12,553.85

Step by Step Solution

1. Step 1: Write the proportion equation
   21,057.72 : 29,049.16 = 12,553.85 : x
2. Step 2: Convert to fraction form
   21,057.72/29,049.16 = 12,553.85/x
3. Step 3: Cross multiply
   21,057.72x = 29,049.16 × 12,553.85
4. Step 4: Simplify right side
   21,057.72x = 364,678,667.71
5. Step 5: Solve for x
   x = 364,678,667.71/21,057.72
6. Step 6: Final answer
   x = 17,318.05