Finding the Fourth Proportional to 1,078.39, 1,487.95 and 685.27

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.39 : 1,487.95 = 685.27 : x
2. Step 2: Convert to fraction form
   1,078.39/1,487.95 = 685.27/x
3. Step 3: Cross multiply
   1,078.39x = 1,487.95 × 685.27
4. Step 4: Simplify right side
   1,078.39x = 1,019,647.50
5. Step 5: Solve for x
   x = 1,019,647.50/1,078.39
6. Step 6: Final answer
   x = 945.53