Kaplan Statistics Final Ch. 1-3 Questions.

Kaplan Statistics Final Ch. 1-3 Questions. Which sampling method divides the population up into sections, randomly selects some of those sections, then chooses all the members from the selected sections to study? - ANSWER Cluster Which sampling method subdivides the population into categories sharing similar characteristics and then selects a sample from each subdivision? - ANSWER Stratified ______ is used when subjects are assigned to different groups through a process of random selection. - ANSWER Randomization A study is conducted to measure children's growth rates without any treatment applied to the children. What best classifies this study? - ANSWER Observational Which of the following corresponds to the case when every sample of size n has the same chance of being chosen? - ANSWER Simple Random Sample Explain the difference between a single-blind and a double-blind experiment. - ANSWER In a single-blind experiment, the subject does not know which treatment is received. In a double-blind experiment, neither the subject nor the researcher in contact with the subject knows which treatment is received. A study of an association between which ear is used for cell phone calls and whether the subject is left-handed or right-handed began with a survey e-mailed to 5000 people belonging to an otology online group, and 717 surveys were returned. (Otology relates to the ear and hearing.) What percentage of the 5000 surveys were returned? Does that response rate appear to be low? In general, what is a problem with a very low response rate? - ANSWER Convert to percentage 14%. It appears to be low. It creates a serious potential for getting a biased sample that consists of those with a special interest in the topic. In a study designed to test the effectiveness of a medication as a treatment for lower back pain, 1643 patients were randomly assigned to one of three groups: (1) the 547 subjects in the placebo group were given pills containing no medication; (2) 550 subjects were in a group given pills with the medication taken at regular intervals; (3) 546 subjects were in a group given pills with the medication to be taken when needed for pain relief. In what specific way was replication applied in the study? - ANSWER The group sample sizes are all large so the researchers could see the effects of the treatment.