Finding the Fourth Proportional to 1,298.28, 1,791.61 and 708.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.28 : 1,791.61 = 708.83 : x
2. Step 2: Convert to fraction form
   1,298.28/1,791.61 = 708.83/x
3. Step 3: Cross multiply
   1,298.28x = 1,791.61 × 708.83
4. Step 4: Simplify right side
   1,298.28x = 1,269,946.92
5. Step 5: Solve for x
   x = 1,269,946.92/1,298.28
6. Step 6: Final answer
   x = 978.18