Variables which take on numerical values and for which measures such as the mean, median, or standard deviation are meaningful are referred to as numerical. Variables which serve to group data into categories are called categorical $$ examples include the color of a car or an area code prefix for a telephone number. Note that a telephone area code looks numeric, but since taking their average is meaningless, we consider it to be categorical. It is possible for data to be neither numerical nor categorical $$ for example, a unique identifier is a non$-$numeric variable which is unique to each record. A timestamp may be an example of a unique identifier $$ all is not lost, however, with a bit of pre$-$processing we can sometimes extract useful information from these columns.

Answer the following using your knowledge of the dataset and variable types.