Finding the Fourth Proportional to 21,456.78, 29,610.81 and 12,028.38

Step by Step Solution

1. Step 1: Write the proportion equation
   21,456.78 : 29,610.81 = 12,028.38 : x
2. Step 2: Convert to fraction form
   21,456.78/29,610.81 = 12,028.38/x
3. Step 3: Cross multiply
   21,456.78x = 29,610.81 × 12,028.38
4. Step 4: Simplify right side
   21,456.78x = 356,170,074.79
5. Step 5: Solve for x
   x = 356,170,074.79/21,456.78
6. Step 6: Final answer
   x = 16,599.42