Finding the Fourth Proportional to 1,080.27, 1,490.54 and 687.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,080.27 : 1,490.54 = 687.87 : x
2. Step 2: Convert to fraction form
   1,080.27/1,490.54 = 687.87/x
3. Step 3: Cross multiply
   1,080.27x = 1,490.54 × 687.87
4. Step 4: Simplify right side
   1,080.27x = 1,025,294.31
5. Step 5: Solve for x
   x = 1,025,294.31/1,080.27
6. Step 6: Final answer
   x = 949.11