Finding the Fourth Proportional to 1,128.52, 1,558.31 and 709.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.52 : 1,558.31 = 709.57 : x
2. Step 2: Convert to fraction form
   1,128.52/1,558.31 = 709.57/x
3. Step 3: Cross multiply
   1,128.52x = 1,558.31 × 709.57
4. Step 4: Simplify right side
   1,128.52x = 1,105,730.03
5. Step 5: Solve for x
   x = 1,105,730.03/1,128.52
6. Step 6: Final answer
   x = 979.81