Finding the Fourth Proportional to 12,178.28, 16,800.54 and 7,142.78

Step by Step Solution

1. Step 1: Write the proportion equation
   12,178.28 : 16,800.54 = 7,142.78 : x
2. Step 2: Convert to fraction form
   12,178.28/16,800.54 = 7,142.78/x
3. Step 3: Cross multiply
   12,178.28x = 16,800.54 × 7,142.78
4. Step 4: Simplify right side
   12,178.28x = 120,002,561.10
5. Step 5: Solve for x
   x = 120,002,561.10/12,178.28
6. Step 6: Final answer
   x = 9,853.82