Finding the Fourth Proportional to 1,205.34, 1,662.30 and 831.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,205.34 : 1,662.30 = 831.72 : x
2. Step 2: Convert to fraction form
   1,205.34/1,662.30 = 831.72/x
3. Step 3: Cross multiply
   1,205.34x = 1,662.30 × 831.72
4. Step 4: Simplify right side
   1,205.34x = 1,382,568.16
5. Step 5: Solve for x
   x = 1,382,568.16/1,205.34
6. Step 6: Final answer
   x = 1,147.04