Aspirin and Cardiovascular Disease. In the article by P. Ridker et al. titled “A Randomized Trial of Low-dose Aspirin in the Primary Prevention of Cardiovascular Disease inWomen” (New England Journal of Medicine, Vol. 352, pp. 1293–1304), the researchers noted that “We randomly assigned 39,876 initially healthy women 45 years of age or older to receive 100 mg of aspirin or placebo on alternate days and then monitored them for 10 years for a first major cardiovascular event (i.e., nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes).”

Popular Diets. In the article “Comparison of the Atkins, Ornish, Weight Watchers, and Zone Diets for Weight Loss and Heart Disease Risk Reduction” (Journal of the American Medical Association, Vol. 293, No. 1, pp. 43–53), M. Dansinger et al. conducted a randomized trial to assess the effectiveness of four popular diets for weight loss. Overweight adults with average body mass index of 35 and ages 22–72 years participated in the randomized trial for 1 year. The weight losses, in kilograms, based on the results of the experiment are given on the WeissStats site. Negative losses are gains. WW = Weight Watchers. a. Obtain individual normal probability plots and the standard deviations of the samples. b. Perform a residual analysis. c. Use your results from parts (a) and (b) to decide whether conducting a one-way ANOVA test on the data is reasonable. If so, also do parts (d) and (e). d. Use a one-way ANOVA test to decide, at the 5% significance level, whether the data provide sufficient…

In a study on the effect of an oral rinse on plaque buildup on teeth, sixteen people whose teeth were thoroughly cleaned and polished were randomly assigned to two groups of eight subjects each. Both groups were assigned to use oral rinses (no brushing) for a 2-week period. Group 1 used a rinse that contained an antiplaque agent. Group 2, the control group, received a similar rinse except that the rinse contained no antiplaque agent. A measure of plaque buildup was recorded at 14 days with means and standard deviations for the two groups shown in the table. Control Group Antiplaque Group Sample Size 8 8. Mean 1.22 0.77 Standard Deviation 0.33 0.33 n USE SALT (a) State the null and alternative hypotheses that should be used to test the effectiveness of the antiplaque oral rinse. O Ho: (H, - H2) = 0 versus H: (, - H2) 0 O Ho: (H1 - H2) = 0 versus H,: (H, - H2) > 0 O Ho: (H1 - H2) = 0 versus H.: (4, - H2) # 0 (b) Do the data provide sufficient evidence to indicate that the oral…

Migraine and Acupuncture: A migraine is a particularly painful type of headache, which patients sometimes wish to treat with acupuncture. To determine whether acupuncture relieves migraine pain, researchers conducted a randomized controlled study where patients diagnosed with migraine headaches were randomly assigned to one of two groups: treatment or control.Patients in the treatment group received acupuncture that is specifically designed to treat migraines and patients in the control group received placebo acupuncture (needle insertion at non-acupoint locations). 24 hours after patients received acupuncture, they were asked if they were pain free. Results are summarized in the contingency table below. Test to see if migraine pain relief is dependent on receiving acupuncture. Test at the 8% level and round expected values to one decimal place. Pain Relief Yes (Observed) Yes (Expected Value) No (Observed) No (Expected Value) Row Total No Relief 29   29   58 Control 91   103…

As a hospital administrator of a large hospital, you are concerned with the absenteeism among nurses' aides. The issue has been raised by registered nurses, who feel they often have to perform work normally done by their aides. To get the facts, absenteeism data were gathered for the last three weeks, which is considered a representative period for future conditions. After taking random samples of 64 personnel files each day, the following data were produced: Because your assessment of absenteeism is likely to come under careful scrutiny, you would like a type I error of only 1 percent. You want to be sure to identify any instances of unusual absences. If some are present, you will have to explore them on behalf of the registered nurses. a. Design a p-chart. The upper control limit is enter your response here and the lower control limit is enter your response here . (Enter your responses rounded to three decimal places. If your answer for the lower control limit is negative, enter…