Finding the Fourth Proportional to 1,128.83, 1,558.34 and 709.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.83 : 1,558.34 = 709.79 : x
2. Step 2: Convert to fraction form
   1,128.83/1,558.34 = 709.79/x
3. Step 3: Cross multiply
   1,128.83x = 1,558.34 × 709.79
4. Step 4: Simplify right side
   1,128.83x = 1,106,085.47
5. Step 5: Solve for x
   x = 1,106,085.47/1,128.83
6. Step 6: Final answer
   x = 979.86