Finding the Fourth Proportional to 21,108.33, 29,142.78 and 13,557.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,108.33 : 29,142.78 = 13,557.72 : x
2. Step 2: Convert to fraction form
   21,108.33/29,142.78 = 13,557.72/x
3. Step 3: Cross multiply
   21,108.33x = 29,142.78 × 13,557.72
4. Step 4: Simplify right side
   21,108.33x = 395,109,651.26
5. Step 5: Solve for x
   x = 395,109,651.26/21,108.33
6. Step 6: Final answer
   x = 18,718.19