Finding the Fourth Proportional to 21,137.43, 29,168.86 and 12,185.31

Step by Step Solution

1. Step 1: Write the proportion equation
   21,137.43 : 29,168.86 = 12,185.31 : x
2. Step 2: Convert to fraction form
   21,137.43/29,168.86 = 12,185.31/x
3. Step 3: Cross multiply
   21,137.43x = 29,168.86 × 12,185.31
4. Step 4: Simplify right side
   21,137.43x = 355,431,601.45
5. Step 5: Solve for x
   x = 355,431,601.45/21,137.43
6. Step 6: Final answer
   x = 16,815.27