Finding the Fourth Proportional to 8,540.31, 12,785.55 and 5,243.41

Step by Step Solution

1. Step 1: Write the proportion equation
   8,540.31 : 12,785.55 = 5,243.41 : x
2. Step 2: Convert to fraction form
   8,540.31/12,785.55 = 5,243.41/x
3. Step 3: Cross multiply
   8,540.31x = 12,785.55 × 5,243.41
4. Step 4: Simplify right side
   8,540.31x = 67,039,880.73
5. Step 5: Solve for x
   x = 67,039,880.73/8,540.31
6. Step 6: Final answer
   x = 7,849.82