Finding the Fourth Proportional to 1,223.43, 1,688.05 and 825.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,223.43 : 1,688.05 = 825.83 : x
2. Step 2: Convert to fraction form
   1,223.43/1,688.05 = 825.83/x
3. Step 3: Cross multiply
   1,223.43x = 1,688.05 × 825.83
4. Step 4: Simplify right side
   1,223.43x = 1,394,042.33
5. Step 5: Solve for x
   x = 1,394,042.33/1,223.43
6. Step 6: Final answer
   x = 1,139.45