Finding the Fourth Proportional to 3,978.27, 5,490.03 and 2,209.90

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.27 : 5,490.03 = 2,209.90 : x
2. Step 2: Convert to fraction form
   3,978.27/5,490.03 = 2,209.90/x
3. Step 3: Cross multiply
   3,978.27x = 5,490.03 × 2,209.90
4. Step 4: Simplify right side
   3,978.27x = 12,132,417.30
5. Step 5: Solve for x
   x = 12,132,417.30/3,978.27
6. Step 6: Final answer
   x = 3,049.67