Finding the Fourth Proportional to 21,843.20, 30,149.88 and 12,892.16

Step by Step Solution

1. Step 1: Write the proportion equation
   21,843.20 : 30,149.88 = 12,892.16 : x
2. Step 2: Convert to fraction form
   21,843.20/30,149.88 = 12,892.16/x
3. Step 3: Cross multiply
   21,843.20x = 30,149.88 × 12,892.16
4. Step 4: Simplify right side
   21,843.20x = 388,697,076.94
5. Step 5: Solve for x
   x = 388,697,076.94/21,843.20
6. Step 6: Final answer
   x = 17,794.88