You wish to study the effect of a tutoring program to help improve student grades in an introductory statistics course. Propose an experimental study design to answer the question.
Q. 2Having a coffee fix just before a workout may not be the best idea, a study suggests. Researchers in Switzerland found that the amount of caffeine in just two cups of coffee limits the body's ability to increase blood flow to the heart during exercise. The study included 18 young, healthy people who were regular coffee drinkers. They did not drink any coffee for 36 hours prior to study testing. The researchers used high-tech PET scans to measure the participants' heart blood flow before and after they rode a stationary bike and then repeated the testing procedure after swallowing a tablet containing 200 milligrams of caffeine -- the amount contained in two cups of coffee. The caffeine did not affect heart blood flow when the participants were inactive. However, measurements taken immediately after exercise showed a slowdown in heart blood flow after they'd taken the caffeine tablets, compared to their previous results. Which variable is the response variable in this study?
a. Caffeine content
b. Physical activity (stationary bike)
c. Difference in heart blood flow
d. Taking a caffeine tablet (yes or no)
Q. 3Having a coffee fix just before a workout may not be the best idea, a study suggests. Researchers in Switzerland found that the amount of caffeine in just two cups of coffee limits the body's ability to increase blood flow to the heart during exercise. The study included 18 young, healthy people who were regular coffee drinkers. They did not drink any coffee for 36 hours prior to study testing. The researchers used high-tech PET scans to measure the participants' heart blood flow before and after they rode a stationary bike and then repeated the testing procedure after swallowing a tablet containing 200 milligrams of caffeine -- the amount contained in two cups of coffee. The caffeine did not affect heart blood flow when the participants were inactive. However, measurements taken immediately after exercise showed a slowdown in heart blood flow after they'd taken the caffeine tablets, compared to their previous results. Which variable is an explanatory variable in this study?
a. The health of the participants
b. Taking a caffeine tablet (yes or no)
c. Difference in heart blood flow
d. The PET scan
Q. 4Having a coffee fix just before a workout may not be the best idea, a study suggests. Researchers in Switzerland found that the amount of caffeine in just two cups of coffee limits the body's ability to increase blood flow to the heart during exercise. The study included 18 young, healthy people who were regular coffee drinkers. They did not drink any coffee for 36 hours prior to study testing. The researchers used high-tech PET scans to measure the participants' heart blood flow before and after they rode a stationary bike and then repeated the testing procedure after swallowing a tablet containing 200 milligrams of caffeine -- the amount contained in two cups of coffee. The caffeine did not affect heart blood flow when the participants were inactive. However, measurements taken immediately after exercise showed a slowdown in heart blood flow after they'd taken the caffeine tablets, compared to their previous results. What type of study is this?
a. Observational study
b. Randomized block design
c. Matched pairs study
d. Repeated measures study
Q. 5Fifty university students are randomly chosen from the college campus. Their physical fitness routines and academic performance will be assessed. They are asked to maintain a diary over a semester to record their physical activity (i.e. work-outs) every week. At the end of this semester their GPA is recorded as well. The resulting information is categorized per student into two variables: physical activity (recorded as above average, average, or below average) and that semester's GPA. The primary interest of the research project is to understand if physical activity promotes better academic performance. Which variable is the explanatory variable in this study?
a. The diary
b. Physical activity
c. GPA
d. Academic performance
Q. 6Fifty university students are randomly chosen from the college campus. Their physical fitness routines and academic performance will be assessed. They are asked to maintain a diary over a semester to record their physical activity (i.e. work-outs) every week. At the end of this semester their GPA is recorded as well. The resulting information is categorized per student into two variables: physical activity (recorded as above average, average, or below average) and that semester's GPA. The primary interest of the research project is to understand if physical activity promotes better academic performance. Which of the following principles was used in this study?
a. Randomization
b. Control
c. Replication
d. Blinding
Q. 7Fifty university students are randomly chosen from the college campus. Their physical fitness routines and academic performance will be assessed. They are asked to maintain a diary over a semester to record their physical activity (i.e. work-outs) every week. At the end of this semester their GPA is recorded as well. The resulting information is categorized per student into two variables: physical activity (recorded as above average, average, or below average) and that semester's GPA. The primary interest of the research project is to understand if physical activity promotes better academic performance. What type of study is this?
a. Observational study
b. Randomized experiment
c. Matched pairs study
d. Repeated measures study
Q. 8A researcher is studying the relationship between sugar consumption and weight gain. Twelve volunteers were randomly assigned to one of two groups. The first group had five participants which were put on a diet low in sugar and the other group with the remaining seven participants received 10 of their calories from sugar. After 8 weeks, weight gain was recorded from each participant. The low sugar' group can be thought of as a control group. The control group is being used in this experiment to avoid
a. Confounding with the 10 sugar' group
b. Placebo effect
c. Nonresponse bias
d. Replication
Q. 9A researcher is studying the relationship between sugar consumption and weight gain. Twelve volunteers were randomly assigned to one of two groups. The first group had five participants which were put on a diet low in sugar and the other group with the remaining seven participants received 10 of their calories from sugar. After 8 weeks, weight gain was recorded from each participant. Which of the following principles was not used in this study?
a. Repeated measures
b. Blinding
c. Randomization
d. Control
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