Finding the Fourth Proportional to 1,081.20, 1,490.85 and 708.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.20 : 1,490.85 = 708.15 : x
2. Step 2: Convert to fraction form
   1,081.20/1,490.85 = 708.15/x
3. Step 3: Cross multiply
   1,081.20x = 1,490.85 × 708.15
4. Step 4: Simplify right side
   1,081.20x = 1,055,745.43
5. Step 5: Solve for x
   x = 1,055,745.43/1,081.20
6. Step 6: Final answer
   x = 976.46