Finding the Fourth Proportional to 2,218.27, 3,327.86 and 831.57

Step by Step Solution

1. Step 1: Write the proportion equation
   2,218.27 : 3,327.86 = 831.57 : x
2. Step 2: Convert to fraction form
   2,218.27/3,327.86 = 831.57/x
3. Step 3: Cross multiply
   2,218.27x = 3,327.86 × 831.57
4. Step 4: Simplify right side
   2,218.27x = 2,767,348.54
5. Step 5: Solve for x
   x = 2,767,348.54/2,218.27
6. Step 6: Final answer
   x = 1,247.53