Finding the Fourth Proportional to 1,399.34, 1,930.34 and 839.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.34 : 1,930.34 = 839.54 : x
2. Step 2: Convert to fraction form
   1,399.34/1,930.34 = 839.54/x
3. Step 3: Cross multiply
   1,399.34x = 1,930.34 × 839.54
4. Step 4: Simplify right side
   1,399.34x = 1,620,597.64
5. Step 5: Solve for x
   x = 1,620,597.64/1,399.34
6. Step 6: Final answer
   x = 1,158.12