In testing the difference between two independent population means,it is assumed that the level of measurement is at least ______________.
A) a ratio variable
B) a qualitative variable
C) an interval variable
D) a categorical variable

Question

Quizplus · Accepted Answer

In order to test the difference between two independent population means, we need to calculate the t-statistic or z-score, which requires the level of measurement to be at least interval scale. This is because the difference between two means should be meaningful and consistent, and only interval or ratio variables provide this type of measurement. Qualitative and categorical variables do not have a consistent unit of measurement, making it impossible to calculate the difference between means. Therefore, choice C, an interval variable, is the best choice for this question.

In Testing the Difference Between Two Independent Population Means,it Is