Finding the Fourth Proportional to 2,558.39, 3,530.67 and 1,439.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,558.39 : 3,530.67 = 1,439.31 : x
2. Step 2: Convert to fraction form
   2,558.39/3,530.67 = 1,439.31/x
3. Step 3: Cross multiply
   2,558.39x = 3,530.67 × 1,439.31
4. Step 4: Simplify right side
   2,558.39x = 5,081,728.64
5. Step 5: Solve for x
   x = 5,081,728.64/2,558.39
6. Step 6: Final answer
   x = 1,986.30