Finding the Fourth Proportional to 8,139.80, 12,216.59 and 6,395.47

Step by Step Solution

1. Step 1: Write the proportion equation
   8,139.80 : 12,216.59 = 6,395.47 : x
2. Step 2: Convert to fraction form
   8,139.80/12,216.59 = 6,395.47/x
3. Step 3: Cross multiply
   8,139.80x = 12,216.59 × 6,395.47
4. Step 4: Simplify right side
   8,139.80x = 78,130,834.85
5. Step 5: Solve for x
   x = 78,130,834.85/8,139.80
6. Step 6: Final answer
   x = 9,598.62