Finding the Fourth Proportional to 2,578.29, 3,558 and 1,399.35

Step by Step Solution

1. Step 1: Write the proportion equation
   2,578.29 : 3,558 = 1,399.35 : x
2. Step 2: Convert to fraction form
   2,578.29/3,558 = 1,399.35/x
3. Step 3: Cross multiply
   2,578.29x = 3,558 × 1,399.35
4. Step 4: Simplify right side
   2,578.29x = 4,978,887.30
5. Step 5: Solve for x
   x = 4,978,887.30/2,578.29
6. Step 6: Final answer
   x = 1,931.08