Vertical banded gastroplasty is a surgical procedure that reduces the volume of the stomach in order to produce weight loss. In a recent study, 82 patients with Type 2 diabetes underwent this procedure, and 59 of them experienced a recovery from diabetes. Does this study provide convincing evidence that the percentage of those with diabetes who undergo this surgery will recover from diabetes differs from 74%? State the null and alternate hypotheses and use the α=0.05 level of significance and the critical value method

Which best illustrates the distinction between statistical significance and practical importance?     Multiple Choice   "This year, 360 of 440 statistics students at Oxnard Technical College rented their textbooks, compared with 110 of 330 students last year. This is a significant increase."     "Our new manufacturing technique has increased the life of the 80 GB USB AsimoDrive external hard disk significantly, from 240,000 hours to 250,000 hours."     "In 50,000 births, the new vaccine reduced the incidence of infant mortality in Morrovia significantly from 14.2 deaths per 1000 births to 10.3 deaths per 1000 births."     "The new Sky Penetrator IV business jet’s cruising range has increased significantly from 3,975 miles to 4,000 miles."

Nutritional researchers conducted an investigation of two high-fiber diets intended to reduce cholesterol level. a group of people with high cholesterol were randomly selected to receive an "rice" diet or a "vegetable" diet for 20 days. Use a t-test to compare the diets at 5% significance level. Null Hypothesis: The means from two respective diets are the same Alternative Hypothesis:  The means from the two diets differ.   Fall in Cholesterol (mg/dL) Diet     n       Mean     SD   Rice 10   14.4 6.8 Vegetable 9   10.57 6.37 do we fail to reject the null hypothesis or reject null hypothesis

Trans-Generational Effects of Diet Can experiences of parents affect future children? New studies16 suggest that they can: Early life experiences of parents appear to cause permanent changes in sperm and eggs. In one study, some male rats were fed a high-fat diet with 43% of calories from fat (a typical American diet), while others were fed a normal healthy rat diet. Not surprisingly, the rats fed the high-fat diet were far more likely than the normal-diet rats to develop metabolic syndrome (characterized by such things as excess weight, excess fat, insulin resistance, and glucose intolerance.) What surprised the scientists was that the daughters of these rats were also far more likely to develop metabolic syndrome than the daughters of rats fed healthy diets. None of the daughters and none of the mothers ate a high-fat diet and the fathers did not have any contact with the daughters. The high-fat diet of the fathers appeared to cause negative effects for their daughters. What are the…

A study is planned to investigate risk factors for sudden cardiac death. A cohort of men and women between the ages of 35 and 70 is enrolled and followed for up to 20 years. As part of the study, participants provide data on demographic and behavioral characteristics; they also undergo testing for cardiac function and provide blood samples to assess lipid profiles and other biomarkers. A new measure of inflammation is hypothesized to be related to sudden cardiac death. Describe its strengths and weaknesses.

A clinical trial is planned to compare an experi- mental medication designed to lower blood pressure to a placebo. Before starting the trial, a pilot study is conducted involving 7 participants. The objective of the study is to assess how systolic blood pressure changes over time untreated. Systolic blood pres- sures are measured at baseline and again 4 weeks later. Is there a statistically significant difference in blood pressures over time? Run the test at a 5% level of significance. Baseline: 120 145 130 160 152 143 126 4 Weeks: 122 142 135 158 155 140 130

A study was made of 413 children who were hospitalized as a result of motor vehicle crashes. Among 290 children who were not using seat belts, 60 were injured severely. Among 123 children using seat belts, 16 were injured severely (based on data from "Morbidity Among Pediatric Motor Vehicle Crash Victims: The Effectiveness of Seat Belts," by Osberg and Di Scala, American Journal of Public Health, Vol. 82, No. 3). For this problem we want to know, is there sufficient sample evidence to conclude, at the 0.05 significance level, that the proportion of severe injuries is higher for children not wearing seat belts? Let pi be the proportion of severe injuries among all children not wearing seatbelts and who were involved in crashes. Let p2 be the proportion of severe injuries among all children wearing seatbelts and who were involved in crashes. Which is the proper expression of Ho? Pi = P2 O Pi P2 Which is the proper expression of H1? O pi P2 Calculate p1 to 4 decimal places: Calculate p,…

A randomized controlled trial was conducted to determine whether treatment with daily aspirin was more effective than placebo at preventing myocardial infarction (MI) (within 5 years).   A total of 140 out of 11,140 subjects in the aspirin group experienced an MI, while 240 out of 11,040 subjects in the placebo group experienced an MI.  The relative risk of MI comparing aspirin to placebo was calculated to be 0.58, and its 95% confidence interval ranged from 0.47 to 0.71.  Which of the following can be concluded from these results?   Question 4 options:   On average, the risk of MI among subjects who used aspirin was 0.58 times the risk of MI among those on placebo.   On average, aspirin reduced the risk of MI in this population by 58% when compared to placebo.   Aspirin is almost certainly harmful to this population.   Compared to placebo, aspirin did not reduce the risk of MI by a statistically significant amount.

Based on the results presented, did the exercise intervention groups still receive a health benefit even if significant weight loss did not occur? Explain.