#### Answer

nominal
ordinal
interval
ratio

#### Work Step by Step

When data is classified into mutually exclusive groups that have no ranking or relative value, this is a nominal level of measurement.
When variables can be ordered but have no precise relative value, this is an ordinal level of measurement.
When variables can be ordered and there is a precise difference between each unit but no true zero, this is an interval level of measurement.
When variables can be ordered and there is a precise difference between each unit and there is a true zero, this is a ratio level of measurement.