Finding the Fourth Proportional to 1,380.27, 1,904.81 and 821.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.27 : 1,904.81 = 821.04 : x
2. Step 2: Convert to fraction form
   1,380.27/1,904.81 = 821.04/x
3. Step 3: Cross multiply
   1,380.27x = 1,904.81 × 821.04
4. Step 4: Simplify right side
   1,380.27x = 1,563,935.94
5. Step 5: Solve for x
   x = 1,563,935.94/1,380.27
6. Step 6: Final answer
   x = 1,133.06