Finding the Fourth Proportional to 21,535.34, 29,721.56 and 12,105.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,535.34 : 29,721.56 = 12,105.72 : x
2. Step 2: Convert to fraction form
   21,535.34/29,721.56 = 12,105.72/x
3. Step 3: Cross multiply
   21,535.34x = 29,721.56 × 12,105.72
4. Step 4: Simplify right side
   21,535.34x = 359,800,822.79
5. Step 5: Solve for x
   x = 359,800,822.79/21,535.34
6. Step 6: Final answer
   x = 16,707.46