Finding the Fourth Proportional to 1,078.83, 1,488.38 and 636.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.83 : 1,488.38 = 636.57 : x
2. Step 2: Convert to fraction form
   1,078.83/1,488.38 = 636.57/x
3. Step 3: Cross multiply
   1,078.83x = 1,488.38 × 636.57
4. Step 4: Simplify right side
   1,078.83x = 947,454.87
5. Step 5: Solve for x
   x = 947,454.87/1,078.83
6. Step 6: Final answer
   x = 878.22