1. A professor offers his 840 students the option of coming to a review session
ID: 3069906 • Letter: 1
Question
1. A professor offers his 840 students the option of coming to a review session the day before the final exam. In order to decide whether the review session actually helps students, he keeps track of who attends the session and compares their average grade on the final exam with that of students who did not attend. This study is a(n)
A) observational study.
B) nonrandomized experiment.
C) completely randomized experiment.
D) randomized block design.
E) matched pairs design.
2. The keys or principles to designing good, convincing experiments are
A) randomization, double-blind technique, and comparison of several treatments.
B) randomization, adequate numbers, and double-blind technique.
C) control, sampling distributions, and double-blind technique.
D) confidence intervals, adequate numbers, and comparison of several treatments.
E) randomization, control, and adequate numbers.
3. An online survey of college parents was conducted. An email was sent to 41,000 parents who were listed in college databases. Parents were invited to participate in the online survey. Out of those invited, 1749 completed the survey. A quick margin of error gave 2.4%. Is this a good measure of accuracy of the survey results? Explain.
A) yes, because the response rate is less than a quarter of the sample size
B) yes, because the study found more than 25% of mothers communicate each day with their child
C) no, because we know nothing about the large group that did not respond to the survey
D) no, because the survey was sent via email
Explanation / Answer
1) ans A observational study
An observationsl study drawn inferences from sample to a population where the independent variable is not under the control of the researcher becausal of ethical concerns or logistics contraints.
2) ans B
randomization , adequate numbers and double blind technique
3)ans C
no,because we know nothing about the large group that did not responce to the survey.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.