Finding the Fourth Proportional to 1,561.97, 2,342.34 and 831.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.97 : 2,342.34 = 831.15 : x
2. Step 2: Convert to fraction form
   1,561.97/2,342.34 = 831.15/x
3. Step 3: Cross multiply
   1,561.97x = 2,342.34 × 831.15
4. Step 4: Simplify right side
   1,561.97x = 1,946,835.89
5. Step 5: Solve for x
   x = 1,946,835.89/1,561.97
6. Step 6: Final answer
   x = 1,246.40