Finding the Fourth Proportional to 6,086.61, 8,399.61 and 3,990.69

Step by Step Solution

1. Step 1: Write the proportion equation
   6,086.61 : 8,399.61 = 3,990.69 : x
2. Step 2: Convert to fraction form
   6,086.61/8,399.61 = 3,990.69/x
3. Step 3: Cross multiply
   6,086.61x = 8,399.61 × 3,990.69
4. Step 4: Simplify right side
   6,086.61x = 33,520,239.63
5. Step 5: Solve for x
   x = 33,520,239.63/6,086.61
6. Step 6: Final answer
   x = 5,507.21