Question

1. a marketing company wants to test out two different versions of an advertising campaign for a new product. they recruited 200 students from a local university who volunteered to participate in an experiment. half of the students were randomly assigned campaign a and the other half received campaign b. each student viewed the campaign and then rated the likelihood that they would buy the product. to which group is it most reasonable to generalize the results of this study? a) all students b) all students from this local university c) all students from this local university who buy similar products. d) all students from this local university who are similar to those who volunteered for the study. e) all people who are similar ages to the volunteers. 6. a recent observational study of more than 5,200 adults found that morning workouts may be better for weight loss. participants wore fitness trackers over a period of two years and also attended regular health check - ins at a doctor’s office. the researchers found that people who exercised early in the morning tended to have lower body mass index (bmi) scores than those that exercised later in the day. a. identify the explanatory variable and the response variable. b. identify a possible confounding variable. c. explain how the confounding variable is associated with the explanatory variable. d. explain how the confounding variable might influence the response variable.

Explanation:

For question 5:

• In an experiment, the sample is from a local university and they volunteered. Generalizing should be to a group similar to the sample.
• Option A is too broad (all students), not just from the local university.
• Option B assumes all students from the local university, but only volunteers (a subset) were in the study.
• Option C adds a new condition (buy similar products) not in the sample description.
• Option E changes the group to people of similar age (not just students).
• Option D is correct as it refers to students from the local university similar to the volunteers (the sample).

For question 6a:

• The explanatory variable is what is being manipulated or considered as a predictor. Here, it's the time of exercise (morning or later in the day).
• The response variable is what is being measured. Here, it's the body mass index (BMI) score.

For question 6b:

• A possible confounding variable could be diet.

For question 6c:

• People who exercise in the morning might have a more structured diet (e.g., eat breakfast regularly, control calorie intake better).

For question 6d:

• A better - controlled diet (as a confounding variable) can directly influence BMI (the response variable) by affecting calorie intake and nutrient balance.

Answer:

1. D. All students from this local university who are similar to those who volunteered for the study.

6a. Explanatory variable: Time of exercise (morning or later in the day). Response variable: Body mass index (BMI) score.
6b. Possible confounding variable: Diet.
6c. People who exercise in the morning may have a more structured diet.
6d. A well - controlled diet can influence BMI by affecting calorie intake and nutrient balance.