Finding the Fourth Proportional to 1,870.88, 2,807.31 and 831.92

Step by Step Solution

1. Step 1: Write the proportion equation
   1,870.88 : 2,807.31 = 831.92 : x
2. Step 2: Convert to fraction form
   1,870.88/2,807.31 = 831.92/x
3. Step 3: Cross multiply
   1,870.88x = 2,807.31 × 831.92
4. Step 4: Simplify right side
   1,870.88x = 2,335,443.30
5. Step 5: Solve for x
   x = 2,335,443.30/1,870.88
6. Step 6: Final answer
   x = 1,248.32