A poll solicits a large number of college undergraduates for

A poll solicits a large number of college undergraduates for information on the following
variables: the name of their cell phone provider (AT&T, Verizon, and so on), the numbers
of minutes used last month (200, 400, for example), and their satisfaction with the service (Terrible, Adequate, Excellent, and so forth). What is the data scale for each of these
three variables?

Solution

Cellphone provider is a nominal variable.

Number of minutes is ratio variable because we can interpret 6 minutes as twice of 3 minutes.

Even thought satisfaction service appears to be nominal variable (with only labels), but these labels are ranked, and thus they are ordinal variable.