Finding the Fourth Proportional to 21,540.33, 29,728.62 and 12,109.50

Step by Step Solution

1. Step 1: Write the proportion equation
   21,540.33 : 29,728.62 = 12,109.50 : x
2. Step 2: Convert to fraction form
   21,540.33/29,728.62 = 12,109.50/x
3. Step 3: Cross multiply
   21,540.33x = 29,728.62 × 12,109.50
4. Step 4: Simplify right side
   21,540.33x = 359,998,723.89
5. Step 5: Solve for x
   x = 359,998,723.89/21,540.33
6. Step 6: Final answer
   x = 16,712.78