Finding the Fourth Proportional to 1,398.10, 1,929.49 and 838.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.10 : 1,929.49 = 838.59 : x
2. Step 2: Convert to fraction form
   1,398.10/1,929.49 = 838.59/x
3. Step 3: Cross multiply
   1,398.10x = 1,929.49 × 838.59
4. Step 4: Simplify right side
   1,398.10x = 1,618,046.83
5. Step 5: Solve for x
   x = 1,618,046.83/1,398.10
6. Step 6: Final answer
   x = 1,157.32