Finding the Fourth Proportional to 139.92, 209.83 and 82.08

Step by Step Solution

1. Step 1: Write the proportion equation
   139.92 : 209.83 = 82.08 : x
2. Step 2: Convert to fraction form
   139.92/209.83 = 82.08/x
3. Step 3: Cross multiply
   139.92x = 209.83 × 82.08
4. Step 4: Simplify right side
   139.92x = 17,222.85
5. Step 5: Solve for x
   x = 17,222.85/139.92
6. Step 6: Final answer
   x = 123.09