Finding the Fourth Proportional to 2,578.30, 3,558.04 and 1,399.37

Step by Step Solution

1. Step 1: Write the proportion equation
   2,578.30 : 3,558.04 = 1,399.37 : x
2. Step 2: Convert to fraction form
   2,578.30/3,558.04 = 1,399.37/x
3. Step 3: Cross multiply
   2,578.30x = 3,558.04 × 1,399.37
4. Step 4: Simplify right side
   2,578.30x = 4,978,993.15
5. Step 5: Solve for x
   x = 4,978,993.15/2,578.30
6. Step 6: Final answer
   x = 1,931.12