The sorted dataset is $\{2, 4, 8, 12, 16, 20, 24, 28, 32, 100\}$.

To find the $20\%$ Winsorized mean, the values $2$ and $4$ are replaced by $8$, and the values $32$ and $100$ are replaced by $28$.

The $20\%$ Winsorized mean of this dataset is $18.0$.

The Winsorized mean ($18.0$) is less than the original arithmetic mean ($24.6$) because the positive outlier $100$ was replaced by a smaller value ($28$).