Finding the Fourth Proportional to 1,298.15, 1,791.48 and 708.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.15 : 1,791.48 = 708.72 : x
2. Step 2: Convert to fraction form
   1,298.15/1,791.48 = 708.72/x
3. Step 3: Cross multiply
   1,298.15x = 1,791.48 × 708.72
4. Step 4: Simplify right side
   1,298.15x = 1,269,664.84
5. Step 5: Solve for x
   x = 1,269,664.84/1,298.15
6. Step 6: Final answer
   x = 978.06