Reading and understanding nutrition labels on foods may be an important precursor to dietary change. Researchers randomly selected four medical clinics in Missouri. A total of 885 patients were asked to complete a survey while waiting to see their physicians. The study found that those who read labels tended to have better diets. Can the researchers conclude that reading nutrition labels on foods causes patients to have better diets? (A) No, because the 885 respondents do not represent a simple random sample. (B) No, this was an observational study so the researchers can only claim an association. (C) Yes, because the use of randomization in the study allows for cause and effect conclusions. (D) Yes, because the sample size of 885 is sufficiently large. (E) The researchers can only claim a cause and effect relationship among individuals similar to the patients who completed the survey.

Identify whether the studies described here are based on (1) single samples, (2) paired samples, or (3) independent samples.   Cardiovascular disease risk factors are compared in husbands and wives. A nutritional exam is applied to a random sample of individuals. Results are compared to the results of the whole nation. An investigator compares vaccination histories in 30 autistic schoolchildren to a simple random sample of non-autistic children from the same school district.

Crime incidents by quarantine violators. On June 10, 2020, CNN Philippines reported that the Philippine National Police (PNP) said that incidents of crime had decreased sharply during the country’s community quarantine, which lasted for 84 days. Concurrently, the Joint Task Force COVID Shield reported that a total of 193,779 quarantine violators had been warned, fined, or arrested. About 65.05% of them were from Luzon. Consider a random sample of 500 quarantine violators. a. Compute m and s for the random variable x, the num- ber of quarantine violators who are from Luzon. b. From the sample of 500 quarantine violators, is it likely that less than half are not from Luzon? Explain.

Acne is a common skin disease that affects most adolescents and can continue into adulthood. A study compared the effectiveness of three acne treatments and a placebo, all in gel form, applied twice daily for 12 weeks. The study's 517 teenage volunteers were randomly assigned to one of the four treatments. Success was assessed as clear or almost clear skin at the end of the 12 week period. The results of the study can be seen in the table below. Using the appropriate statistical test, determine if there is significant evidence that the four treatments perform differently. If so, how do they compare.

A hospital claims that 40% of its patients request a telephone. you are interested in disproving this claim. you select a random sample of 250 patients and find that 85% requested a telephone. what is the test statistic for this test?

Researchers asked soda drinkers to view either the logo for their favorite soda or a graphic warning demonstrating the harmful effects of sugary beverages (e.g., tooth decay, obesity) and then measured their negative mood with a short survey. They found that those participants who saw the warnings reported significantly greater negative moods than those who saw the logos. Which statistical test should be used?

Most alpine skiers and snowboarders do not use helmets. Do helmetsreduce the risk of head injuries? A study in Norway compared skiers and snowboarders who suffered head injuries with a control group who were not injured. Of 578 injured subjects, 96 had worn a helmet. Of the 2992 in the control group, 656 wore helmets. Is helmet use less common among skiers and snowboarders who have head injuries?

A ski company in Vail owns two ski shops, one on the west side and one on the east side of Vail. Ski hat sales data (in dollars) for a random sample of 5 Saturdays during the ski season showed the following results. Is there a significant difference in sales dollars of hats between the west side and east side stores at the 10 percent level of significance?  Saturday Sales Data ($) for Ski Hats Saturday East Side Shop West Side Shop 1 548 523 2 493 721 3 609 695 4 567 510 5 432 532       Click here for the Excel Data File (a) Choose the appropriate hypotheses. Assume μd is the difference in average sales between the east side shop and west side shop. a. H0: μd = 0 versus H1: μd ≠ 0.b. H0: μd ≠ 0 versus H1: μd = 0. multiple choice a b         Ski Hat Sales on Five  Consecutive Saturdays (n = 5)               Saturday East Side West Side       1 548 523       2 493 721       3 609 695       4 567 510       5 432 532

The state highway department is studying traffic patterns on one of the busiest highways in the state. As part of the study. the department needs to estimate the average number of vehicles that pass an intersection each day. One of the department's officer (Officer A) claims that on average, more than 15,000 cars passing the intersection. On the other hand. Officer B claims that on average, 18,000 cars passing the intersection. Meanwhile, a random sample of 64 days gives a sample mean of 14,205 cars and a sample standard deviation of 1,010 cars. Test both claim at 0.05 level of significance. Use the critical value approach and show the complete calculation steps for each testing. Whose claim is true? Testing Officer A's claim Step 1: State the hypotheses Step 2: Find critical value and state the decision rule Step 3: Compute the test value Step 4: Make decision Step 5: Conclusion Testing Officer B's claim Step 1: State the hypotheses Step 2: Find critical value and state the decision…

A ski company in Vail owns two ski shops, one on the west side and one on the east side of Vail. Ski hat sales data (in dollars) for a random sample of 5 Saturdays during the ski season showed the following results. Is there a significant difference in sales dollars of hats between the west side and east side stores at the 10 percent level of significance?  Saturday Sales Data ($) for Ski Hats Saturday East Side Shop West Side Shop 1 548 523 2 493 721 3 609 695 4 567 510 5 432 532       Click here for the Excel Data File  (b) State the decision rule for 10 percent level of significance. (Round your answers to 3 decimal places.)      (c-1) Find the test statistic tcalc. (Round your answer to 2 decimal places. A negative value should be indicated by a minus sign.)      (c-2) What is your conclusion?           Ski Hat Sales on Five  Consecutive Saturdays (n = 5)               Saturday East Side West Side       1 548 523       2 493 721       3 609 695…