Finding the Fourth Proportional to 2,680.16, 4,020.86 and 831.18

Step by Step Solution

1. Step 1: Write the proportion equation
   2,680.16 : 4,020.86 = 831.18 : x
2. Step 2: Convert to fraction form
   2,680.16/4,020.86 = 831.18/x
3. Step 3: Cross multiply
   2,680.16x = 4,020.86 × 831.18
4. Step 4: Simplify right side
   2,680.16x = 3,342,058.41
5. Step 5: Solve for x
   x = 3,342,058.41/2,680.16
6. Step 6: Final answer
   x = 1,246.96