Finding the Fourth Proportional to 1,398.73, 1,930.09 and 809.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.73 : 1,930.09 = 809.15 : x
2. Step 2: Convert to fraction form
   1,398.73/1,930.09 = 809.15/x
3. Step 3: Cross multiply
   1,398.73x = 1,930.09 × 809.15
4. Step 4: Simplify right side
   1,398.73x = 1,561,722.67
5. Step 5: Solve for x
   x = 1,561,722.67/1,398.73
6. Step 6: Final answer
   x = 1,116.53