Finding the Fourth Proportional to 1,398.38, 1,929.88 and 808.92

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.38 : 1,929.88 = 808.92 : x
2. Step 2: Convert to fraction form
   1,398.38/1,929.88 = 808.92/x
3. Step 3: Cross multiply
   1,398.38x = 1,929.88 × 808.92
4. Step 4: Simplify right side
   1,398.38x = 1,561,118.53
5. Step 5: Solve for x
   x = 1,561,118.53/1,398.38
6. Step 6: Final answer
   x = 1,116.38