Finding the Fourth Proportional to 12,786.31, 19,178.12 and 3,427.31

Step by Step Solution

1. Step 1: Write the proportion equation
   12,786.31 : 19,178.12 = 3,427.31 : x
2. Step 2: Convert to fraction form
   12,786.31/19,178.12 = 3,427.31/x
3. Step 3: Cross multiply
   12,786.31x = 19,178.12 × 3,427.31
4. Step 4: Simplify right side
   12,786.31x = 65,729,399.69
5. Step 5: Solve for x
   x = 65,729,399.69/12,786.31
6. Step 6: Final answer
   x = 5,140.61