Author Question: Which of the following statistical studies is an experimental study? 1.A researcher observes the ... (Read 89 times)

cnetterville · **on:** Jul 24, 2018

Which of the following statistical studies is an experimental study?
1.A researcher observes the effect of alcohol consumption on reaction time by administering various quantities of alcohol to randomly-selected subjects.
2.A study is conducted to see if exposure to increased carbon dioxide levels increases tomato yields. Tomato plants are selected at random and are then exposed to various doses of carbon dioxide.
3.Two random samples of senior adults are selected. The first group watches a 30-minute presentation on Medicare fraud, while the other group does not watch the presentation. A survey is then administered to measure the level of confidence the subjects have in their health care providers.
4.All of these are experimental studies.
5.None of these are experimental studies.

Question 2

Which of the following statistical studies is an observational study?
1.A group of students is surveyed to determine the percentage who believe in reincarnation.
2.A random sample of students is shown a documentary on the evolution of reincarnation beliefs throughout human history. A second random sample is not shown the documentary. The object of the study is to determine whether viewing the documentary affects belief in reincarnation.
3.To determine whether Vitamin C has any effectiveness at lessening the duration of the common cold, one set of cold sufferers is given no Vitamin C, a second set is given 2 grams per day, and a third set is given 5 grams of Vitamin C per day.
4.All of these studies are observational.
5.None of these studies is observational.