Finding the Fourth Proportional to 3,909.20, 5,865.60 and 2,061.20

Step by Step Solution

1. Step 1: Write the proportion equation
   3,909.20 : 5,865.60 = 2,061.20 : x
2. Step 2: Convert to fraction form
   3,909.20/5,865.60 = 2,061.20/x
3. Step 3: Cross multiply
   3,909.20x = 5,865.60 × 2,061.20
4. Step 4: Simplify right side
   3,909.20x = 12,090,174.72
5. Step 5: Solve for x
   x = 12,090,174.72/3,909.20
6. Step 6: Final answer
   x = 3,092.75