Finding the Fourth Proportional to 1,099.50, 1,517.31 and 685.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,099.50 : 1,517.31 = 685.74 : x
2. Step 2: Convert to fraction form
   1,099.50/1,517.31 = 685.74/x
3. Step 3: Cross multiply
   1,099.50x = 1,517.31 × 685.74
4. Step 4: Simplify right side
   1,099.50x = 1,040,480.16
5. Step 5: Solve for x
   x = 1,040,480.16/1,099.50
6. Step 6: Final answer
   x = 946.32