검증된 단계별 안내
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05:11In Exercises 9–20, identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster.
Criminology Researchers randomly selected 50 convicted felons from each category of burglary, auto theft, and assault.
In Exercises 29–32, indicate whether the observational study used is cross-sectional, retrospective, or prospective.
Marijuana Study Researchers from the National Institutes of Health want to determine the current rates of marijuana consumption among adults living in states that have legalized the use of marijuana. They conduct a survey of 500 adults in those states.
In Exercises 9–20, identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster.
Highway Strength The New York State Department of Transportation evaluated the quality of the New York State Thruway by testing core samples collected at regular intervals of 1 mile.
In Exercises 29–32, indicate whether the observational study used is cross-sectional, retrospective, or prospective.
Heart Health Study Samples of subjects with and without heart disease were selected, and then researchers looked back in time to determine whether they took aspirin on a regular basis.
In Exercises 33–36, identify which of these designs is most appropriate for the given experiment: completely randomized design, randomized block design, or matched pairs design.
West Nile Vaccine Currently, there is no approved vaccine for the prevention of infection by West Nile virus. A clinical trial of a possible vaccine is being planned to include subjects treated with the vaccine while other subjects are given a placebo.
In Exercises 13–20, determine whether the results appear to have statistical significance, and also determine whether the results appear to have practical significance.
Election Fraud The County Clerk in Essex County, New Jersey, was responsible for randomly assigning the order in which candidates’ names appeared on a recent election ballot. Among 41 different ballots, a Democrat was placed on the first line 40 times, and a Republican was placed on the first line once.
