Quiz Please refer to the following for the questions number 1 and 2 The Physicians Health Study followed 22,000 male physicians for a period of several years. About 11,000 took an aspirin every second day while the rest took a placebo. At the completion of the study, it was noted whether a subject had experienced a heart attack during the period of the study. It was found that the aspirin group had significantly fewer heart attacks than the placebo group. 1. The factor in the experiment is a. the severity of the heart attack. b. use of a placebo. c. medication used (aspirin or placebo). d. the length of the study. 2. The response variable in this experiment is a. whether a heart attack occurred. b. the placebo effect. c. whether the symptoms lessened. d. the length of the interview. 3. A study attempts to determine whether a football lled with helium when kicked travels farther than one that is filled with air. Each subject kicks twice - once with a football filled with helium and once with a football lled with air. The order of the type of football kicked is randomized. This is an example of a. a matched pairs experiment. b. a double blind observational study. c. a stratied analysis. d. the placebo effect. 4. One hundred volunteers who suffer from agoraphobia are available for a study. Fifty are selected at random and are given the drug imipramine, which is believed to be effective in treating agoraphobia. The other 50 are given a placebo. A psychiatrist evaluates the symptoms of all volunteers after two months to determine if there has been substantial improvement in the severity of the symptoms. This study would be double blind if a. neither drug had any identifying marks on it. b. Neither the volunteers nor the psychiatrist were allowed to see each other during the session during which the psychiatrist evaluated the severity of the symptoms. c. neither the volunteers nor the psychiatrist knew which subjects had received the placebo. d. all of the above. 5 A study examines the personal goals of children in grades 4, 5, and 6. A random sample of students was selected for each of the grades 4, 5, and 6 from schools in Georgia. The students received a questionnaire regarding achievement of personal goals. They were asked what they would most like to do at school: make good grades, be good at sports, or be popular. Results are presented in the following table by the sex of the child. Lou m Make good grades 96 295 Be popular 32 45 Be good in sports 94 40 Which hypotheses are being tested by the chi-square test? a. The null hypothesis is that personal goals and gender are independent, and the alternative is that they are dependent. b. The null hypothesis is that the mean personal goal is the same for boys and girls, and the alternative is that the means differ. c. The distribution of personal goals is different for boys and girls. d. The distribution of gender is different for the three different personal goals. Please refer to the Chapter 26 (Non parametric Tests) for the answers of 6 thru 10. Some researchers have suggested that stempitting disease in peach tree seedlings can be controlled with soil treatment. An experiment was conducted to compare peach tree seedling growth with soil and weeds treated with one of two herbicides. In an experimental field containing 12 seedlings, six were randomly selected throughout the field to receive Herbicide A. The remaining six received Herbicide B. Soil and weed for each seedling were treated with the appropriate herbicide for three months, at which point the height in centimeters was recorded for each seedling. The following results were obtained. Herbicide Height (cm) A 97,93,91,91,89,87 B 91,87,84,78,74,69 E -prodfleet02xythos.content.blackboardcdn.Com