Finding the Fourth Proportional to 12,757.28, 19,139.76 and 3,993.12

Step by Step Solution

1. Step 1: Write the proportion equation
   12,757.28 : 19,139.76 = 3,993.12 : x
2. Step 2: Convert to fraction form
   12,757.28/19,139.76 = 3,993.12/x
3. Step 3: Cross multiply
   12,757.28x = 19,139.76 × 3,993.12
4. Step 4: Simplify right side
   12,757.28x = 76,427,358.45
5. Step 5: Solve for x
   x = 76,427,358.45/12,757.28
6. Step 6: Final answer
   x = 5,990.88