Finding the Fourth Proportional to 1,078.52, 1,488.47 and 636.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.52 : 1,488.47 = 636.57 : x
2. Step 2: Convert to fraction form
   1,078.52/1,488.47 = 636.57/x
3. Step 3: Cross multiply
   1,078.52x = 1,488.47 × 636.57
4. Step 4: Simplify right side
   1,078.52x = 947,512.17
5. Step 5: Solve for x
   x = 947,512.17/1,078.52
6. Step 6: Final answer
   x = 878.53