Finding the Fourth Proportional to 1,279.48, 1,765.94 and 831.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,279.48 : 1,765.94 = 831.91 : x
2. Step 2: Convert to fraction form
   1,279.48/1,765.94 = 831.91/x
3. Step 3: Cross multiply
   1,279.48x = 1,765.94 × 831.91
4. Step 4: Simplify right side
   1,279.48x = 1,469,103.15
5. Step 5: Solve for x
   x = 1,469,103.15/1,279.48
6. Step 6: Final answer
   x = 1,148.20