Finding the Fourth Proportional to 8,139.72, 12,209.56 and 7,040.82

Step by Step Solution

1. Step 1: Write the proportion equation
   8,139.72 : 12,209.56 = 7,040.82 : x
2. Step 2: Convert to fraction form
   8,139.72/12,209.56 = 7,040.82/x
3. Step 3: Cross multiply
   8,139.72x = 12,209.56 × 7,040.82
4. Step 4: Simplify right side
   8,139.72x = 85,965,314.24
5. Step 5: Solve for x
   x = 85,965,314.24/8,139.72
6. Step 6: Final answer
   x = 10,561.21