Finding the Fourth Proportional to 1,078.37, 1,488.17 and 636.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.37 : 1,488.17 = 636.30 : x
2. Step 2: Convert to fraction form
   1,078.37/1,488.17 = 636.30/x
3. Step 3: Cross multiply
   1,078.37x = 1,488.17 × 636.30
4. Step 4: Simplify right side
   1,078.37x = 946,924.16
5. Step 5: Solve for x
   x = 946,924.16/1,078.37
6. Step 6: Final answer
   x = 878.11