Finding the Fourth Proportional to 21,116.16, 29,139.89 and 11,684.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,116.16 : 29,139.89 = 11,684.72 : x
2. Step 2: Convert to fraction form
   21,116.16/29,139.89 = 11,684.72/x
3. Step 3: Cross multiply
   21,116.16x = 29,139.89 × 11,684.72
4. Step 4: Simplify right side
   21,116.16x = 340,491,469.91
5. Step 5: Solve for x
   x = 340,491,469.91/21,116.16
6. Step 6: Final answer
   x = 16,124.69