Finding the Fourth Proportional to 2,809.82, 4,215.28 and 1,078.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,809.82 : 4,215.28 = 1,078.31 : x
2. Step 2: Convert to fraction form
   2,809.82/4,215.28 = 1,078.31/x
3. Step 3: Cross multiply
   2,809.82x = 4,215.28 × 1,078.31
4. Step 4: Simplify right side
   2,809.82x = 4,545,386.42
5. Step 5: Solve for x
   x = 4,545,386.42/2,809.82
6. Step 6: Final answer
   x = 1,617.68