Finding the Fourth Proportional to 1,298.10, 1,791.42 and 708.65

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.10 : 1,791.42 = 708.65 : x
2. Step 2: Convert to fraction form
   1,298.10/1,791.42 = 708.65/x
3. Step 3: Cross multiply
   1,298.10x = 1,791.42 × 708.65
4. Step 4: Simplify right side
   1,298.10x = 1,269,484.89
5. Step 5: Solve for x
   x = 1,269,484.89/1,298.10
6. Step 6: Final answer
   x = 977.96