Finding the Fourth Proportional to 1,398.83, 1,929.42 and 838.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.83 : 1,929.42 = 838.89 : x
2. Step 2: Convert to fraction form
   1,398.83/1,929.42 = 838.89/x
3. Step 3: Cross multiply
   1,398.83x = 1,929.42 × 838.89
4. Step 4: Simplify right side
   1,398.83x = 1,618,571.14
5. Step 5: Solve for x
   x = 1,618,571.14/1,398.83
6. Step 6: Final answer
   x = 1,157.09