Finding the Fourth Proportional to 1,440.16, 1,987.31 and 810.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,440.16 : 1,987.31 = 810.59 : x
2. Step 2: Convert to fraction form
   1,440.16/1,987.31 = 810.59/x
3. Step 3: Cross multiply
   1,440.16x = 1,987.31 × 810.59
4. Step 4: Simplify right side
   1,440.16x = 1,610,893.61
5. Step 5: Solve for x
   x = 1,610,893.61/1,440.16
6. Step 6: Final answer
   x = 1,118.55