Finding the Fourth Proportional to 1,561.24, 2,342.86 and 831.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.24 : 2,342.86 = 831.32 : x
2. Step 2: Convert to fraction form
   1,561.24/2,342.86 = 831.32/x
3. Step 3: Cross multiply
   1,561.24x = 2,342.86 × 831.32
4. Step 4: Simplify right side
   1,561.24x = 1,947,666.38
5. Step 5: Solve for x
   x = 1,947,666.38/1,561.24
6. Step 6: Final answer
   x = 1,247.51