Finding the Fourth Proportional to 1,139.83, 1,710.66 and 831.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.83 : 1,710.66 = 831.82 : x
2. Step 2: Convert to fraction form
   1,139.83/1,710.66 = 831.82/x
3. Step 3: Cross multiply
   1,139.83x = 1,710.66 × 831.82
4. Step 4: Simplify right side
   1,139.83x = 1,422,961.20
5. Step 5: Solve for x
   x = 1,422,961.20/1,139.83
6. Step 6: Final answer
   x = 1,248.40