Finding the Fourth Proportional to 21,357, 29,472.36 and 12,409.54

Step by Step Solution

1. Step 1: Write the proportion equation
   21,357 : 29,472.36 = 12,409.54 : x
2. Step 2: Convert to fraction form
   21,357/29,472.36 = 12,409.54/x
3. Step 3: Cross multiply
   21,357x = 29,472.36 × 12,409.54
4. Step 4: Simplify right side
   21,357x = 365,738,310.10
5. Step 5: Solve for x
   x = 365,738,310.10/21,357
6. Step 6: Final answer
   x = 17,124.99