Finding the Fourth Proportional to 1,111.31, 1,533.73 and 831.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.31 : 1,533.73 = 831.05 : x
2. Step 2: Convert to fraction form
   1,111.31/1,533.73 = 831.05/x
3. Step 3: Cross multiply
   1,111.31x = 1,533.73 × 831.05
4. Step 4: Simplify right side
   1,111.31x = 1,274,606.32
5. Step 5: Solve for x
   x = 1,274,606.32/1,111.31
6. Step 6: Final answer
   x = 1,146.94