Finding the Fourth Proportional to 21,168.84, 29,205.72 and 12,216.18

Step by Step Solution

1. Step 1: Write the proportion equation
   21,168.84 : 29,205.72 = 12,216.18 : x
2. Step 2: Convert to fraction form
   21,168.84/29,205.72 = 12,216.18/x
3. Step 3: Cross multiply
   21,168.84x = 29,205.72 × 12,216.18
4. Step 4: Simplify right side
   21,168.84x = 356,782,332.55
5. Step 5: Solve for x
   x = 356,782,332.55/21,168.84
6. Step 6: Final answer
   x = 16,854.13