Finding the Fourth Proportional to 1,251.50, 1,727.15 and 831.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,251.50 : 1,727.15 = 831.15 : x
2. Step 2: Convert to fraction form
   1,251.50/1,727.15 = 831.15/x
3. Step 3: Cross multiply
   1,251.50x = 1,727.15 × 831.15
4. Step 4: Simplify right side
   1,251.50x = 1,435,516.57
5. Step 5: Solve for x
   x = 1,435,516.57/1,251.50
6. Step 6: Final answer
   x = 1,147.04