Finding the Fourth Proportional to 8,322.78, 12,479.34 and 3,940.20

Step by Step Solution

1. Step 1: Write the proportion equation
   8,322.78 : 12,479.34 = 3,940.20 : x
2. Step 2: Convert to fraction form
   8,322.78/12,479.34 = 3,940.20/x
3. Step 3: Cross multiply
   8,322.78x = 12,479.34 × 3,940.20
4. Step 4: Simplify right side
   8,322.78x = 49,171,095.47
5. Step 5: Solve for x
   x = 49,171,095.47/8,322.78
6. Step 6: Final answer
   x = 5,908.01