Finding the Fourth Proportional to 21,540.69, 29,728.82 and 12,109.25

Step by Step Solution

1. Step 1: Write the proportion equation
   21,540.69 : 29,728.82 = 12,109.25 : x
2. Step 2: Convert to fraction form
   21,540.69/29,728.82 = 12,109.25/x
3. Step 3: Cross multiply
   21,540.69x = 29,728.82 × 12,109.25
4. Step 4: Simplify right side
   21,540.69x = 359,993,818.18
5. Step 5: Solve for x
   x = 359,993,818.18/21,540.69
6. Step 6: Final answer
   x = 16,712.27