Finding the Fourth Proportional to 21,661.38, 29,892.71 and 12,230.55

Step by Step Solution

1. Step 1: Write the proportion equation
   21,661.38 : 29,892.71 = 12,230.55 : x
2. Step 2: Convert to fraction form
   21,661.38/29,892.71 = 12,230.55/x
3. Step 3: Cross multiply
   21,661.38x = 29,892.71 × 12,230.55
4. Step 4: Simplify right side
   21,661.38x = 365,604,284.29
5. Step 5: Solve for x
   x = 365,604,284.29/21,661.38
6. Step 6: Final answer
   x = 16,878.16