Question

collecting and organizing data
where in a data table should units of measurement be shown?
in a separate column after the column of data values
in the headings of columns that list the data values
in a note next to an asterisk, below the table
in parentheses, in the title of the table

Explanation:

In a data table, units of measurement are typically shown in the headings of columns that list the data values. This is a standard practice in data organization (e.g., in scientific or statistical data tables) to clearly associate the units with the corresponding data column. The other options: a separate column after data values is not standard, a note with an asterisk is for additional info not primary units, and the title's parentheses are for table - wide context not per - column units.

Answer:

in the headings of columns that list the data values