Finding the Fourth Proportional to 8,311.80, 12,456.90 and 3,377.40

Step by Step Solution

1. Step 1: Write the proportion equation
   8,311.80 : 12,456.90 = 3,377.40 : x
2. Step 2: Convert to fraction form
   8,311.80/12,456.90 = 3,377.40/x
3. Step 3: Cross multiply
   8,311.80x = 12,456.90 × 3,377.40
4. Step 4: Simplify right side
   8,311.80x = 42,071,934.06
5. Step 5: Solve for x
   x = 42,071,934.06/8,311.80
6. Step 6: Final answer
   x = 5,061.71