Finding the Fourth Proportional to 1,398.54, 1,930.33 and 839.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.54 : 1,930.33 = 839.37 : x
2. Step 2: Convert to fraction form
   1,398.54/1,930.33 = 839.37/x
3. Step 3: Cross multiply
   1,398.54x = 1,930.33 × 839.37
4. Step 4: Simplify right side
   1,398.54x = 1,620,261.09
5. Step 5: Solve for x
   x = 1,620,261.09/1,398.54
6. Step 6: Final answer
   x = 1,158.54