Finding the Fourth Proportional to 1,078.50, 1,488.27 and 636.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.50 : 1,488.27 = 636.30 : x
2. Step 2: Convert to fraction form
   1,078.50/1,488.27 = 636.30/x
3. Step 3: Cross multiply
   1,078.50x = 1,488.27 × 636.30
4. Step 4: Simplify right side
   1,078.50x = 946,986.20
5. Step 5: Solve for x
   x = 946,986.20/1,078.50
6. Step 6: Final answer
   x = 878.06