Question

Researchers were interested in knowing if preterm infants with late metabolic acidosis and preterm infants without the condition differ with respect to urine levels of a certain chemical. The mean levels, standard deviations, and sample sizes for the two samples studied were as follows.

Sample n x s
With condition 35 8.5 5.5
Without condition 40 4.8 3.6

a. What is the explanatory variable in this study and is it categorical or quantitative?
b. What is the response variable in this study and and is it categorical or quantitative?

Answer 1

a. The explanatory variable is categorical.

b. The response variable is quantitative.

Explanation:

The response variable is the focus of a question in a study or experiment. In this case, the response variable is the difference in urine levels of a certain chemical. It is a numerical value (quantitative).

An explanatory variable is one that explains changes in that variable. In the case of this study, the condition of the infants in respect to late metabolic acidosis. This is a categorical variable, as it has two possible categories ("With" and "Without").