Finding the Fourth Proportional to 3,978.13, 5,489.71 and 2,209.69

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.13 : 5,489.71 = 2,209.69 : x
2. Step 2: Convert to fraction form
   3,978.13/5,489.71 = 2,209.69/x
3. Step 3: Cross multiply
   3,978.13x = 5,489.71 × 2,209.69
4. Step 4: Simplify right side
   3,978.13x = 12,130,557.29
5. Step 5: Solve for x
   x = 12,130,557.29/3,978.13
6. Step 6: Final answer
   x = 3,049.31