Finding the Fourth Proportional to 1,078.53, 1,488.30 and 636.35

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.53 : 1,488.30 = 636.35 : x
2. Step 2: Convert to fraction form
   1,078.53/1,488.30 = 636.35/x
3. Step 3: Cross multiply
   1,078.53x = 1,488.30 × 636.35
4. Step 4: Simplify right side
   1,078.53x = 947,079.71
5. Step 5: Solve for x
   x = 947,079.71/1,078.53
6. Step 6: Final answer
   x = 878.12