Finding the Fourth Proportional to 1,040.31, 1,436.77 and 708.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,040.31 : 1,436.77 = 708.15 : x
2. Step 2: Convert to fraction form
   1,040.31/1,436.77 = 708.15/x
3. Step 3: Cross multiply
   1,040.31x = 1,436.77 × 708.15
4. Step 4: Simplify right side
   1,040.31x = 1,017,454.95
5. Step 5: Solve for x
   x = 1,017,454.95/1,040.31
6. Step 6: Final answer
   x = 978.03