Finding the Fourth Proportional to 2,578.83, 3,558.72 and 1,399.87

Step by Step Solution

1. Step 1: Write the proportion equation
   2,578.83 : 3,558.72 = 1,399.87 : x
2. Step 2: Convert to fraction form
   2,578.83/3,558.72 = 1,399.87/x
3. Step 3: Cross multiply
   2,578.83x = 3,558.72 × 1,399.87
4. Step 4: Simplify right side
   2,578.83x = 4,981,745.37
5. Step 5: Solve for x
   x = 4,981,745.37/2,578.83
6. Step 6: Final answer
   x = 1,931.79