Finding the Fourth Proportional to 1,333.56, 1,839.80 and 809.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,333.56 : 1,839.80 = 809.40 : x
2. Step 2: Convert to fraction form
   1,333.56/1,839.80 = 809.40/x
3. Step 3: Cross multiply
   1,333.56x = 1,839.80 × 809.40
4. Step 4: Simplify right side
   1,333.56x = 1,489,134.12
5. Step 5: Solve for x
   x = 1,489,134.12/1,333.56
6. Step 6: Final answer
   x = 1,116.66