Finding the Fourth Proportional to 2,080.15, 3,119.92 and 781.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,080.15 : 3,119.92 = 781.31 : x
2. Step 2: Convert to fraction form
   2,080.15/3,119.92 = 781.31/x
3. Step 3: Cross multiply
   2,080.15x = 3,119.92 × 781.31
4. Step 4: Simplify right side
   2,080.15x = 2,437,630.54
5. Step 5: Solve for x
   x = 2,437,630.54/2,080.15
6. Step 6: Final answer
   x = 1,171.85