Q$6$: Use groupby to get the mean tip by smoker $(2$ pts$.)$

What was the mean tip for smokers $($Yes$)$ vs$.$ non$-$smokers $($No$)?$ Use groupby to calculate this and save the result in a variable called grouped$\_$data.

Note: The grouped$\_$data variable should be the result of calling groupby and then mean, which will contain the mean values.