On a survey, age was divided into three categories: younger than 18 years, 18 to 21 years, and older than 21 years. The researcher computed the mean age of the respondents by adding up the scores and then dividing by the number of cases. Why was this a mistake?
A) because the data are interval-ratio and should not be treated as ordinal
B) because the data are only nominal and should not be treated as ordinal
C) because the data are continuous and should not be treated as discrete
D) because the data are ordinal and should not be treated as interval-ratio data

Question

Quizplus · Accepted Answer

The age categories are ordinal, meaning they have a meaningful order but no consistent interval between them. Calculating a mean assumes interval-ratio data, which is inappropriate for ordinal data.

On a Survey, Age Was Divided into Three Categories: Younger