Finding the Fourth Proportional to 21,156.88, 29,196.20 and 12,204.40

Step by Step Solution

1. Step 1: Write the proportion equation
   21,156.88 : 29,196.20 = 12,204.40 : x
2. Step 2: Convert to fraction form
   21,156.88/29,196.20 = 12,204.40/x
3. Step 3: Cross multiply
   21,156.88x = 29,196.20 × 12,204.40
4. Step 4: Simplify right side
   21,156.88x = 356,322,103.28
5. Step 5: Solve for x
   x = 356,322,103.28/21,156.88
6. Step 6: Final answer
   x = 16,841.90