Finding the Fourth Proportional to 2,578.30, 3,558.03 and 1,399.38

Step by Step Solution

1. Step 1: Write the proportion equation
   2,578.30 : 3,558.03 = 1,399.38 : x
2. Step 2: Convert to fraction form
   2,578.30/3,558.03 = 1,399.38/x
3. Step 3: Cross multiply
   2,578.30x = 3,558.03 × 1,399.38
4. Step 4: Simplify right side
   2,578.30x = 4,979,017.43
5. Step 5: Solve for x
   x = 4,979,017.43/2,578.30
6. Step 6: Final answer
   x = 1,931.13