Finding the Fourth Proportional to 2,559.21, 3,531.89 and 1,440.25

Step by Step Solution

1. Step 1: Write the proportion equation
   2,559.21 : 3,531.89 = 1,440.25 : x
2. Step 2: Convert to fraction form
   2,559.21/3,531.89 = 1,440.25/x
3. Step 3: Cross multiply
   2,559.21x = 3,531.89 × 1,440.25
4. Step 4: Simplify right side
   2,559.21x = 5,086,806.20
5. Step 5: Solve for x
   x = 5,086,806.20/2,559.21
6. Step 6: Final answer
   x = 1,987.65