Finding the Fourth Proportional to 2,558.31, 3,529.86 and 1,439.03

Step by Step Solution

1. Step 1: Write the proportion equation
   2,558.31 : 3,529.86 = 1,439.03 : x
2. Step 2: Convert to fraction form
   2,558.31/3,529.86 = 1,439.03/x
3. Step 3: Cross multiply
   2,558.31x = 3,529.86 × 1,439.03
4. Step 4: Simplify right side
   2,558.31x = 5,079,574.44
5. Step 5: Solve for x
   x = 5,079,574.44/2,558.31
6. Step 6: Final answer
   x = 1,985.52