Finding the Fourth Proportional to 1,078.58, 1,488.63 and 630.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.58 : 1,488.63 = 630.50 : x
2. Step 2: Convert to fraction form
   1,078.58/1,488.63 = 630.50/x
3. Step 3: Cross multiply
   1,078.58x = 1,488.63 × 630.50
4. Step 4: Simplify right side
   1,078.58x = 938,573.77
5. Step 5: Solve for x
   x = 938,573.77/1,078.58
6. Step 6: Final answer
   x = 870.20