Finding the Fourth Proportional to 1,398.55, 1,930.04 and 809.13

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.55 : 1,930.04 = 809.13 : x
2. Step 2: Convert to fraction form
   1,398.55/1,930.04 = 809.13/x
3. Step 3: Cross multiply
   1,398.55x = 1,930.04 × 809.13
4. Step 4: Simplify right side
   1,398.55x = 1,561,653.27
5. Step 5: Solve for x
   x = 1,561,653.27/1,398.55
6. Step 6: Final answer
   x = 1,116.62