Finding the Fourth Proportional to 21,081.60, 29,086.92 and 12,131.64

Step by Step Solution

1. Step 1: Write the proportion equation
   21,081.60 : 29,086.92 = 12,131.64 : x
2. Step 2: Convert to fraction form
   21,081.60/29,086.92 = 12,131.64/x
3. Step 3: Cross multiply
   21,081.60x = 29,086.92 × 12,131.64
4. Step 4: Simplify right side
   21,081.60x = 352,872,042.15
5. Step 5: Solve for x
   x = 352,872,042.15/21,081.60
6. Step 6: Final answer
   x = 16,738.39