Finding the Fourth Proportional to 21,057.72, 31,609.30 and 18,732.56

Step by Step Solution

1. Step 1: Write the proportion equation
   21,057.72 : 31,609.30 = 18,732.56 : x
2. Step 2: Convert to fraction form
   21,057.72/31,609.30 = 18,732.56/x
3. Step 3: Cross multiply
   21,057.72x = 31,609.30 × 18,732.56
4. Step 4: Simplify right side
   21,057.72x = 592,123,108.81
5. Step 5: Solve for x
   x = 592,123,108.81/21,057.72
6. Step 6: Final answer
   x = 28,119.05