Finding the Fourth Proportional to 1,078.77, 1,488.81 and 636.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.77 : 1,488.81 = 636.82 : x
2. Step 2: Convert to fraction form
   1,078.77/1,488.81 = 636.82/x
3. Step 3: Cross multiply
   1,078.77x = 1,488.81 × 636.82
4. Step 4: Simplify right side
   1,078.77x = 948,103.98
5. Step 5: Solve for x
   x = 948,103.98/1,078.77
6. Step 6: Final answer
   x = 878.88