Finding the Fourth Proportional to 2,105.57, 3,158.45 and 806.95

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.57 : 3,158.45 = 806.95 : x
2. Step 2: Convert to fraction form
   2,105.57/3,158.45 = 806.95/x
3. Step 3: Cross multiply
   2,105.57x = 3,158.45 × 806.95
4. Step 4: Simplify right side
   2,105.57x = 2,548,711.23
5. Step 5: Solve for x
   x = 2,548,711.23/2,105.57
6. Step 6: Final answer
   x = 1,210.46