Finding the Fourth Proportional to 1,398.83, 1,929.66 and 839.03

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.83 : 1,929.66 = 839.03 : x
2. Step 2: Convert to fraction form
   1,398.83/1,929.66 = 839.03/x
3. Step 3: Cross multiply
   1,398.83x = 1,929.66 × 839.03
4. Step 4: Simplify right side
   1,398.83x = 1,619,042.63
5. Step 5: Solve for x
   x = 1,619,042.63/1,398.83
6. Step 6: Final answer
   x = 1,157.43