Question

Alec wants to study the relationship between gender and resting heart rate among all adults in Chicago. He randomly selects 100 students at Northwestern University and invites them to participate in his study. For each participant, he records their gender, and then measures their resting heart rate in beats/minute.

A. What kind of study is this: an observational study-sample survey, an observational study-census, or an experiment?

B. What is the population?

C. What is the sample?

D. List each of the variables that are collected in this study and label them as categorical or numerical

Answer 1

Answer

(A) It is a case of observational study sample survey because data is observed for 100 students at Northwestern University. There is no specific treatment given to students, So it is only observational study sample survey.

(B) We know that the population is always the large group from which we select different samples. In this case, 100 students at Northwestern university are selected out of all adults in Chicaco. So, population is all adults in Chicago.

(C) We know that the population is always the large group from which we select different samples. In this case, 100 students at Northwestern university are selected out of all adults in Chicaco. So, sample is 100 students which are selected out of all adults in Chicago.

(D) Two variables are used in this observational study sample survey, which are gender and resting heart rate. We know that numerical variable has mathematical value whereas categorical variable has non-numerical values, i.e. words.

So, gender is categorical value because it can be only male or female

resting heart rate will be numerical value because it can take values like 60, 80 , etc.