Finding the Fourth Proportional to 2,072.43, 3,108.75 and 685.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,072.43 : 3,108.75 = 685.89 : x
2. Step 2: Convert to fraction form
   2,072.43/3,108.75 = 685.89/x
3. Step 3: Cross multiply
   2,072.43x = 3,108.75 × 685.89
4. Step 4: Simplify right side
   2,072.43x = 2,132,260.54
5. Step 5: Solve for x
   x = 2,132,260.54/2,072.43
6. Step 6: Final answer
   x = 1,028.87