Finding the Fourth Proportional to 139.71, 209.56 and 82.33

Step by Step Solution

1. Step 1: Write the proportion equation
   139.71 : 209.56 = 82.33 : x
2. Step 2: Convert to fraction form
   139.71/209.56 = 82.33/x
3. Step 3: Cross multiply
   139.71x = 209.56 × 82.33
4. Step 4: Simplify right side
   139.71x = 17,251.98
5. Step 5: Solve for x
   x = 17,251.98/139.71
6. Step 6: Final answer
   x = 123.49