Finding the Fourth Proportional to 1,040.16, 1,559.42 and 519.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,040.16 : 1,559.42 = 519.89 : x
2. Step 2: Convert to fraction form
   1,040.16/1,559.42 = 519.89/x
3. Step 3: Cross multiply
   1,040.16x = 1,559.42 × 519.89
4. Step 4: Simplify right side
   1,040.16x = 810,732.06
5. Step 5: Solve for x
   x = 810,732.06/1,040.16
6. Step 6: Final answer
   x = 779.43