Finding the Fourth Proportional to 2,558.76, 3,531.12 and 1,439.67

Step by Step Solution

1. Step 1: Write the proportion equation
   2,558.76 : 3,531.12 = 1,439.67 : x
2. Step 2: Convert to fraction form
   2,558.76/3,531.12 = 1,439.67/x
3. Step 3: Cross multiply
   2,558.76x = 3,531.12 × 1,439.67
4. Step 4: Simplify right side
   2,558.76x = 5,083,647.53
5. Step 5: Solve for x
   x = 5,083,647.53/2,558.76
6. Step 6: Final answer
   x = 1,986.76