Finding the Fourth Proportional to 1,298.36, 1,791.72 and 708.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.36 : 1,791.72 = 708.89 : x
2. Step 2: Convert to fraction form
   1,298.36/1,791.72 = 708.89/x
3. Step 3: Cross multiply
   1,298.36x = 1,791.72 × 708.89
4. Step 4: Simplify right side
   1,298.36x = 1,270,123.43
5. Step 5: Solve for x
   x = 1,270,123.43/1,298.36
6. Step 6: Final answer
   x = 978.25