Finding the Fourth Proportional to 1,420.57, 1,960.38 and 831.22

Step by Step Solution

1. Step 1: Write the proportion equation
   1,420.57 : 1,960.38 = 831.22 : x
2. Step 2: Convert to fraction form
   1,420.57/1,960.38 = 831.22/x
3. Step 3: Cross multiply
   1,420.57x = 1,960.38 × 831.22
4. Step 4: Simplify right side
   1,420.57x = 1,629,500.75
5. Step 5: Solve for x
   x = 1,629,500.75/1,420.57
6. Step 6: Final answer
   x = 1,147.08