Finding the Fourth Proportional to 1,318.05, 1,978.56 and 831.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,318.05 : 1,978.56 = 831.38 : x
2. Step 2: Convert to fraction form
   1,318.05/1,978.56 = 831.38/x
3. Step 3: Cross multiply
   1,318.05x = 1,978.56 × 831.38
4. Step 4: Simplify right side
   1,318.05x = 1,644,925.32
5. Step 5: Solve for x
   x = 1,644,925.32/1,318.05
6. Step 6: Final answer
   x = 1,248.00