Finding the Fourth Proportional to 3,978.30, 5,490.08 and 2,406.09

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.30 : 5,490.08 = 2,406.09 : x
2. Step 2: Convert to fraction form
   3,978.30/5,490.08 = 2,406.09/x
3. Step 3: Cross multiply
   3,978.30x = 5,490.08 × 2,406.09
4. Step 4: Simplify right side
   3,978.30x = 13,209,626.59
5. Step 5: Solve for x
   x = 13,209,626.59/3,978.30
6. Step 6: Final answer
   x = 3,320.42