Finding the Fourth Proportional to 2,578.42, 3,558.22 and 1,399.49

Step by Step Solution

1. Step 1: Write the proportion equation
   2,578.42 : 3,558.22 = 1,399.49 : x
2. Step 2: Convert to fraction form
   2,578.42/3,558.22 = 1,399.49/x
3. Step 3: Cross multiply
   2,578.42x = 3,558.22 × 1,399.49
4. Step 4: Simplify right side
   2,578.42x = 4,979,698.70
5. Step 5: Solve for x
   x = 4,979,698.70/2,578.42
6. Step 6: Final answer
   x = 1,931.30