A value of 'middle-aged' in an attribute that otherwise contains peoples' ages in number of years would be an example of _______.

• A. Missing data
• B. Outliers
• C. Inconsistent data
• D. Valid data

Answer: (C)

This question tests data quality and type consistency. An age attribute is expected to hold numeric values (years). Seeing a non-numeric label like “middle-aged” violates the numeric domain, so the value is inconsistent with the rest of the data. It isn’t missing data since something is present, and it isn’t an outlier in the numeric sense because it isn’t a numeric value at all. To fix this, you’d clean the data by converting or removing the non-numeric entry, or adjust the schema to use a categorical age grouping if that better fits the analysis.