Finding the Fourth Proportional to 1,078.71, 1,487.73 and 685.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.71 : 1,487.73 = 685.05 : x
2. Step 2: Convert to fraction form
   1,078.71/1,487.73 = 685.05/x
3. Step 3: Cross multiply
   1,078.71x = 1,487.73 × 685.05
4. Step 4: Simplify right side
   1,078.71x = 1,019,169.44
5. Step 5: Solve for x
   x = 1,019,169.44/1,078.71
6. Step 6: Final answer
   x = 944.80