Finding the Fourth Proportional to 3,978.56, 5,489.52 and 2,406.64

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.56 : 5,489.52 = 2,406.64 : x
2. Step 2: Convert to fraction form
   3,978.56/5,489.52 = 2,406.64/x
3. Step 3: Cross multiply
   3,978.56x = 5,489.52 × 2,406.64
4. Step 4: Simplify right side
   3,978.56x = 13,211,298.41
5. Step 5: Solve for x
   x = 13,211,298.41/3,978.56
6. Step 6: Final answer
   x = 3,320.62