Finding the Fourth Proportional to 2,559.20, 3,531.60 and 1,440.18

Step by Step Solution

1. Step 1: Write the proportion equation
   2,559.20 : 3,531.60 = 1,440.18 : x
2. Step 2: Convert to fraction form
   2,559.20/3,531.60 = 1,440.18/x
3. Step 3: Cross multiply
   2,559.20x = 3,531.60 × 1,440.18
4. Step 4: Simplify right side
   2,559.20x = 5,086,139.69
5. Step 5: Solve for x
   x = 5,086,139.69/2,559.20
6. Step 6: Final answer
   x = 1,987.40