Finding the Fourth Proportional to 3,978.32, 5,489.78 and 2,209.68

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.32 : 5,489.78 = 2,209.68 : x
2. Step 2: Convert to fraction form
   3,978.32/5,489.78 = 2,209.68/x
3. Step 3: Cross multiply
   3,978.32x = 5,489.78 × 2,209.68
4. Step 4: Simplify right side
   3,978.32x = 12,130,646.02
5. Step 5: Solve for x
   x = 12,130,646.02/3,978.32
6. Step 6: Final answer
   x = 3,049.19