Finding the Fourth Proportional to 6,321.60, 8,727.12 and 4,086.78

Step by Step Solution

1. Step 1: Write the proportion equation
   6,321.60 : 8,727.12 = 4,086.78 : x
2. Step 2: Convert to fraction form
   6,321.60/8,727.12 = 4,086.78/x
3. Step 3: Cross multiply
   6,321.60x = 8,727.12 × 4,086.78
4. Step 4: Simplify right side
   6,321.60x = 35,665,819.47
5. Step 5: Solve for x
   x = 35,665,819.47/6,321.60
6. Step 6: Final answer
   x = 5,641.90