Finding the Fourth Proportional to 1,078.25, 1,488.25 and 636.29

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.25 : 1,488.25 = 636.29 : x
2. Step 2: Convert to fraction form
   1,078.25/1,488.25 = 636.29/x
3. Step 3: Cross multiply
   1,078.25x = 1,488.25 × 636.29
4. Step 4: Simplify right side
   1,078.25x = 946,951.15
5. Step 5: Solve for x
   x = 946,951.15/1,078.25
6. Step 6: Final answer
   x = 878.23