Definitions

are numbers with a

• are the objects described in a set of data. are sometimes people. When the objects that we want to study are not people, we often call them .
• A  is any characteristic of an . A  can take different values for different .

1. A places an individual into one of two or more groups or categories.
2. A takes numerical values for which arithmetic operations such as adding and averaging make sense.
3. The of a variable tells us what values it takes and how often it takes these values.