Finding the Fourth Proportional to 1,139.66, 1,573.12 and 708.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.66 : 1,573.12 = 708.83 : x
2. Step 2: Convert to fraction form
   1,139.66/1,573.12 = 708.83/x
3. Step 3: Cross multiply
   1,139.66x = 1,573.12 × 708.83
4. Step 4: Simplify right side
   1,139.66x = 1,115,066.78
5. Step 5: Solve for x
   x = 1,115,066.78/1,139.66
6. Step 6: Final answer
   x = 978.42