Finding the Fourth Proportional to 20,128.18, 27,768.24 and 12,165.78

Step by Step Solution

1. Step 1: Write the proportion equation
   20,128.18 : 27,768.24 = 12,165.78 : x
2. Step 2: Convert to fraction form
   20,128.18/27,768.24 = 12,165.78/x
3. Step 3: Cross multiply
   20,128.18x = 27,768.24 × 12,165.78
4. Step 4: Simplify right side
   20,128.18x = 337,822,298.83
5. Step 5: Solve for x
   x = 337,822,298.83/20,128.18
6. Step 6: Final answer
   x = 16,783.55