Question

For each of the following five scenarios, identify (a) the individuals, (b) the type of each variable according to its measurement, (c) the response and explanatory variables and (d) and whether the study is an experiment or an observational study. Explain

Scenario A. It is posited that babies born at different times of the year may develop the ability to crawl at different ages. Thirty two babies born in January crawled at an average age of 29.75 weeks, with a standard deviation of 7 weeks. Another 32 babies born in August crawled at an average of 33.5 weeks with a standard deviation of 7 weeks.

Scenario B. One hundred students in a large statistics class at a university were asked to describe their political position and whether they had engaged in binge drinking. Do people who engage in binge drinking tend to have certain political positions?

Scenario C. Researchers timed 20 subjects as they tried to complete paper-andpencil mazes. Each subject attempted a maze both with and without the presence of a floral aroma. Subjects were randomized with respect to whether they did the scented trial first or second. Is there any evidence that the floral scent improved the subjects’ ability to complete the mazes?

Scenario D. Given that postsecondary education in France is essentially free and that postsecondary education in the US is very expensive, a researcher wonders whether the total number of education years for French people is higher than that of Americans. Randomly chosen people in France and the US are asked for their number of years of education.

Scenario E. Computers in some vehicles calculate various quantities related to performance. One of these is the fuel efficiency. For 50 randomly sampled vehicles equipped in this way, the number of liters per 100 kilometers driven were recorded.

Answer 1