Finding the Fourth Proportional to 3,978.37, 5,490.16 and 2,209.97

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.37 : 5,490.16 = 2,209.97 : x
2. Step 2: Convert to fraction form
   3,978.37/5,490.16 = 2,209.97/x
3. Step 3: Cross multiply
   3,978.37x = 5,490.16 × 2,209.97
4. Step 4: Simplify right side
   3,978.37x = 12,133,103.25
5. Step 5: Solve for x
   x = 12,133,103.25/3,978.37
6. Step 6: Final answer
   x = 3,049.77