Finding the Fourth Proportional to 1,398.09, 1,929.48 and 808.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.09 : 1,929.48 = 808.83 : x
2. Step 2: Convert to fraction form
   1,398.09/1,929.48 = 808.83/x
3. Step 3: Cross multiply
   1,398.09x = 1,929.48 × 808.83
4. Step 4: Simplify right side
   1,398.09x = 1,560,621.31
5. Step 5: Solve for x
   x = 1,560,621.31/1,398.09
6. Step 6: Final answer
   x = 1,116.25