Finding the Fourth Proportional to 3,978.11, 5,489.96 and 2,209.88

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.11 : 5,489.96 = 2,209.88 : x
2. Step 2: Convert to fraction form
   3,978.11/5,489.96 = 2,209.88/x
3. Step 3: Cross multiply
   3,978.11x = 5,489.96 × 2,209.88
4. Step 4: Simplify right side
   3,978.11x = 12,132,152.80
5. Step 5: Solve for x
   x = 12,132,152.80/3,978.11
6. Step 6: Final answer
   x = 3,049.73