please solve these questions:-
The press release referenced in the previous exercise also included data from independent surveys of teenage drivers and parents of teenage drivers. In response to a question asking if they approved of laws banning the use of cell phones and texting while driving. 74% of the teens surveyed and 95%% of the parents surveyed said they approved. The sample sizes were not given in the press release, but for purposes of this exercise, suppose that 800 teens and 400 parents of teens responded to the surveys and that it is reasonable to regard these samples as representative of the two populations. Do the data provide convincing evidence that the proportion of teens that approve of cell-phone and texting bans while driving is less than the proportion of parents of teens who approve? Test the relevant hypotheses using a significance level of .05.The article "Fish Oil Staves Off Schizophrenia" (USA Today, February 2. 2010) describes a study in which 81 patients age 13 to 25 who were considered atrisk for mental illness were randomly assigned to one of two groups. Those in one group took four fish oil capsules daily. The other group took a placebo. After 1 year, 5% of those in the fish oil group and 28% of those in the placebo group had become psychotic. Is it appropriate to use the two-sample z test of this section to test hypotheses about the difference in the proportions of patients receiving the fish oil and the placebo treatments who became psychotic? Explain why or why not.The report "Young People Living on the Edge" (Greenberg Quinlan Rosner Research, 2008) summarizes a survey of people in two independent random samples. One sample consisted of 800 young adults (age 19 to 35) and the other sample consisted of 300 parents of children age 19 to 35. The young adults were presented with a variety of situations (such as getting married or buying a house) and were asked if they thought that their parents were likely to provide financial support in that situation. The parents of young adults were presented with the same situations and asked if they would be likely to provide financial support to their child in that situation. a. When asked about getting married. 41% of the young adults said they thought parents would provide financial support and 43%% of the parents said they would provide support. Carry out a hypothesis test to determine if there is convincing evidence that the proportion of young adults who think parents would provide financial support and the proportion of parents who say they would provide support are different. b. The report stated that the proportion of young adults who thought parents would help with buying a house or apartment was .37. For the sample of parents, the proportion who said they would help with buying a house or an apartment was 27. Based on these data, can you conclude that the proportion of parents who say they would help with buying a house or an apartment is significantly less than the proportion of young adults who think that their parents would help?"Doctors Praise Device That Aids Ailing Hearts" (Associated Press, November 0, 2004) is the headline of an article that describes the results of a study of the effectiveness of a fabric device that acts like a support stocking for a weak or damaged heart. In the study, 107 people who consented to treatment were assigned at random to either a standard treatment consisting of drugs or the experimental treatment that consisted of drugs plus surgery to install the stocking- After two years, 38% of the 57 patients receiving the stocking had improved and 27% of the patients receiving the standard treatment had improved. Do these data provide convincing evidence that the proportion of patients who improve is higher for the experimental treatment than for the standard treatment? Test the relevant hypotheses using a significance level of .05.The following quote is from the article "Canadians Are Healthier Than We Are" (Associated Press, May 31, 2006): "The Americans also reported more heart disease and major depression. but those differences were too small to be statistically significant." This statement was based on the responses of a sample of 5183 Americans and a sample of 3505 Canadians. The proportion of Canadians who reported major depression was given as .082. a. Assuming that the researchers used a one-sided test with a significance level of .05, could the sample proportion of Americans reporting major depression have been as large as .09? Explain why or why not. b. Assuming that the researchers used a significance level of .05, could the sample proportion of Americans reporting major depression have been as large as .10? Explain why or why not.Women diagnosed with breast cancer whose tumors have not spread may be faced with a decision between two surgical treatments-mastectomy (removal of the breast) or lumpectomy (only the tumor is removed). In a long-term study of the effectiveness of these two treatments, 701 women with breast cancer were randomly assigned to one of two treatment groups. One group received mastectomies and the other group received lumpectomies and radiation. Both groups were followed for 20 years after surgery. It was reported that there was no statistically significant difference in the proportion surviving for 20 years for the two treatments (Associated Press, October 17, 2002). What hypotheses do you think the researchers tested in order to reach the given conclusion? Did the researchers reject or fail to reject the null hypothesis?In December 2001, the Department of Veterans Affairs announced that it would begin paying benefits to soldiers suffering from Lou Gehrig's disease who had served in the Gulf War (The New York Times, December 11, 2001). This decision was based on an analysis in which the Lou Gehrig's disease incidence rate (the proportion developing the disease) for the approximately 700,000 soldiers sent to the Gulf between August 1980 and July 1991 was compared to the incidence rate for the approximately 1.8 million other soldiers who were not in the Gulf during this time period. Based on these data, explain why it is not appropriate to perform a formal inference procedure (such as the two-sample z test) and yet it is still reasonable to conclude that the incidence rate is higher for Gulf War veterans than for those who did not serve in the Gulf War.A deficiency of the trace element selenium in the diet can negatively impact growth, immunity. muscle and neuromuscular function, and fertility. The introduction of selenium supplements to dairy cows is justified when pastures have low selenium levels. Authors of the paper "Effects of Short-Term Supplementation with Selenised Yeast on Milk Production and Composition of Lactating Cows" (Australian Journal of Dairy Technology. [2004]: 109-203) supplied the following data on milk selenium concentration (mg/L) for a sample of cows given a selenium supplement (the treatment group) and a control sample given no supplement, both initially and after a 9-day period. Inalmend Incalmont 1475 94 123 12.4 2.5 102 109 132.3 1.7 125 1178 121. 3. Use the given data for the treatment group to determine if there is sufficient evidence to conclude that the mean selenium concentration is greater after 9 days of the selenium supplement. b. Are the data for the cows in the control group (no selenium supplement) consistent with the hypothesis of no significant change in mean selenium concentration over the 9-day period? c. Would you use the paired t test to determine if there was a significant difference in the initial mean selenium concentration for the control group and the treatment group? Explain why or why noThe article "A 'White" Name Found to Help in Job Search" (Associated Press, January 15, 2003) described an experiment to investigate if it helps to have a "white-sounding" first name when looking for a job. Researchers sent 5000 resumes in response to ads that appeared in the Boston Globe and Chicago Tribune. The resumes were identical except that 2500 of them had "white-sounding" first names, such as Brett and Emily, whereas the other 2500 had "black- sounding"names such as Tamika and Rasheed. Resumes of the first type elicited 250 responses and resumes of the second type only 187 responses. Do these data support the theory that the proportion receiving responses is higher for those resumes with "white-sounding first" names?A deficiency of the trace element selenium in the diet can negatively impact growth, immunity. muscle and neuromuscular function, and fertility. The introduction of selenium supplements to dairy cows is justified when pastures have low selenium levels. Authors of the paper "Effects of Short-Term Supplementation with Selenised Yeast on Milk Production and Composition of Lactating Cows" (Australian Journal of Dairy Technology. [2004]: 109-203) supplied the following data on milk selenium concentration (mg/L) for a sample of cows given a selenium supplement (the treatment group) and a control sample given no supplement, both initially and after a 9-day period. held Meupment Inalment 114 10.3 10. 1473 104 12.4 10.3 102 109 132.3 1.7 125 117 8 121.3 a. Use the given data for the treatment group to determine if there is sufficient evidence to conclude that the mean selenium concentration is greater after 9 days of the selenium supplement. b. Are the data for the cows in the control group (no selenium supplement) consistent with the hypothesis of no significant change in mean selenium concentration over the 9-day period? c. Would you use the paired t test to determine if there was a significant difference in the initial mean selenium concentration for the control group and the treatment group? Explain why or why not.The Oregon Department of Health web site provides information on the cost-to-charge ratio (the percentage of billed charges that are actual costs to the hospital). The cost-to-charge ratios for both inpatient and outpatient care in 2002 for a sample of six hospitals in Oregon follow. Inprikent Quipaibni Rail 75 71 71 Oregon hospitals is lower for outpatient care than for inpatient care? Use a significance level of .05
