Final answer:
For a table with missing data such as an ethnicity category of 'Other/Unknown', a bar graph should be used to represent the data because it clearly shows each category independently and accounts for omitted data without the misleading impression of completeness a pie chart might convey.
Step-by-step explanation:
When depicting missing data in a table, such as the Ethnicity of Students without the Other/Unknown category, it is important to choose the correct type of visual representation. Since the frequencies do not add up to the total number of students, it's advised to create a bar graph rather than a pie chart. A bar graph can accommodate categories with omitted data by showing each category's frequency independently, making it clear that some data points are missing. Additionally, a bar graph does not mislead the viewer into thinking that the shown percentages add up to 100%, which is important in the case of missing or unclassified responses. Remember to include a category for 'Other/Unknown' to indicate the omitted segment and ensure that all possible responses are represented, maintaining the integrity of the visual data representation.