Finding the Fourth Proportional to 2,558.30, 3,530.30 and 1,439.28

Step by Step Solution

1. Step 1: Write the proportion equation
   2,558.30 : 3,530.30 = 1,439.28 : x
2. Step 2: Convert to fraction form
   2,558.30/3,530.30 = 1,439.28/x
3. Step 3: Cross multiply
   2,558.30x = 3,530.30 × 1,439.28
4. Step 4: Simplify right side
   2,558.30x = 5,081,090.18
5. Step 5: Solve for x
   x = 5,081,090.18/2,558.30
6. Step 6: Final answer
   x = 1,986.12