Finding the Fourth Proportional to 1,078.35, 1,488.28 and 636.29

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.35 : 1,488.28 = 636.29 : x
2. Step 2: Convert to fraction form
   1,078.35/1,488.28 = 636.29/x
3. Step 3: Cross multiply
   1,078.35x = 1,488.28 × 636.29
4. Step 4: Simplify right side
   1,078.35x = 946,977.68
5. Step 5: Solve for x
   x = 946,977.68/1,078.35
6. Step 6: Final answer
   x = 878.17