Finding the Fourth Proportional to 2,578.37, 3,558.17 and 1,399.43

Step by Step Solution

1. Step 1: Write the proportion equation
   2,578.37 : 3,558.17 = 1,399.43 : x
2. Step 2: Convert to fraction form
   2,578.37/3,558.17 = 1,399.43/x
3. Step 3: Cross multiply
   2,578.37x = 3,558.17 × 1,399.43
4. Step 4: Simplify right side
   2,578.37x = 4,979,409.84
5. Step 5: Solve for x
   x = 4,979,409.84/2,578.37
6. Step 6: Final answer
   x = 1,931.22