Finding the Fourth Proportional to 21,061.88, 31,601.41 and 13,569.35

Step by Step Solution

1. Step 1: Write the proportion equation
   21,061.88 : 31,601.41 = 13,569.35 : x
2. Step 2: Convert to fraction form
   21,061.88/31,601.41 = 13,569.35/x
3. Step 3: Cross multiply
   21,061.88x = 31,601.41 × 13,569.35
4. Step 4: Simplify right side
   21,061.88x = 428,810,592.78
5. Step 5: Solve for x
   x = 428,810,592.78/21,061.88
6. Step 6: Final answer
   x = 20,359.56