Finding the Fourth Proportional to 1,355.52, 1,870.66 and 831.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.52 : 1,870.66 = 831.25 : x
2. Step 2: Convert to fraction form
   1,355.52/1,870.66 = 831.25/x
3. Step 3: Cross multiply
   1,355.52x = 1,870.66 × 831.25
4. Step 4: Simplify right side
   1,355.52x = 1,554,986.13
5. Step 5: Solve for x
   x = 1,554,986.13/1,355.52
6. Step 6: Final answer
   x = 1,147.15