viruses typically cause common colds. In a test of the effectiveness of​ echinacea, 31 of the 38 subjects treated with echinacea developed rhinovirus infections. In a placebo​ group,83 of the 97 subjects developed rhinovirus infections. Use a 0.01 significance level to test the claim that echinacea has an effect on rhinovirus infections.  a. Identify the test statistic. z equals  ​(Round to two decimal places as​ needed.) b. Identify the​ P-value. ​P-value equals ​(Round to three decimal places as​ needed.)   c. Test the claim by constructing an appropriate confidence interval

Do larger universities tend to have more property crime? University crime statistics are affected by a variety of factors. The surrounding community, accessibility given to outside visitors, and many other factors influence crime rate. Let x be a variable that represents student enrollment (in thousands) on a university campus, and let y be a variable that represents the number of burglaries in a year on the university campus. A random sample of n = 8 universities in California gave the following information about enrollments and annual burglary incidents. x 13.3 28.6 24.5 14.3 7.5 27.7 16.2 20.1 y 25 75 39 23 15 30 15 25 Use a calculator to verify that Σx = 152.2, Σx2 = 3289.58, Σy = 247, Σy2 = 10275 and Σxy = 5450.9. Compute r. (Round your answer to four decimal places.)

Use the results from a survey of a simple random sample of  1045 adults. Among the  ​1045 respondents, ​92% rated themselves as above average drivers. We want to test the claim that  4/5 of adults rate themselves as above average drivers. Complete parts​ (a) through​ (c).                                                                                                                                                                                                                                                                                                                            a. Identify the actual number of respondents who rated themselves as above average drivers.

The recidivism rate for convicted sex offenders is 15%. A warden suspects that this percent is higher if the sex offender is also a drug addict. Of the 377 convicted sex offenders who were also drug addicts, 64 of them became repeat offenders. What can be concluded at the a = 0.01 level of significance?

B. Your process has a normal histogram with mean located at 10 mm, 1s points at 9.9 and 10.1 mm, 2s points at 9.8 and 10.2 mm, and 3s points at 9.7 and 10.3 mm. Construct a histogram and discuss the importance of sigma as a measure of variation.

In the world population, 81.2% of all people have dark brown or black hair, 10.3% have brown hair, 6.3% have blond hair and 2.2% have red, gray, or white hair. A researcher wants to see if the distribution of hair color is different for the residents of Nashville. The table below shows the results of a random sample of 568 residents in Nashville. What can be concluded at the significant level of a = 0.01.

A headache medicine is tested on an experimental group of 50 patients who have headaches. Out of these people, 37 of them say they felt better when taking the medicine. A fake pill (placebo) is given to 50 different patients, of whom 27 say they felt better after taking the "medicine". Is this enough evidence to show that a higher percentage of people in the experimental group were cured, compared to the control group? (Use a = .01) Type of Test: Hypotheses: Test Statistic: P-value: Decision: XC. In a sentence, what can be said about the medicine?

Television networks rely heavily on ratings of TV shows when deciding whether to renew a show for another season. Suppose a network has decided that "Miniature Golf with the Stars" will only be renewed if it can be established that more than 12% of U.S. adults watch the show. A polling company asks a random sample of 2000 U.S. adults if they watch "Miniature Golf with the Stars." The network uses the data to perform a test of Ho: p = 0.12 H₁ : p > 0.12 where p is the true proportion of all U.S. adults who watch the show. Which of the following is not true regarding Type I and Type II errors in this setting? A Type I occurs if the television network finds convincing evidence that the true proportion of U.S. adults who watch "Miniature Golf with the Stars" is greater than 0.12, when it is really equal to 0.12. The probability of making a Type II error would be reduced if a smaller a level was chosen. A possible consequence of a Type I error here is the show will renew for another season…

Using the same anti-venom study, answer the following questions. A study was done on children (6 months to 18 years of age) who had (nonlethal) scorpion stings. Researchers wanted to know the effectiveness of a new anti-venonm. Each child was randomly assigned to receive a shot of the anti-venom or a placebo shot. Researchers recorded whether or not their condition improved over the next four hours. a. Identify the population for the study. b. Identify the sample for the study. (HINT: See #1) c. Was this an observational study or a controlled experiment? Explain how you know. d. Assuming the rest of the study was well-designed, use your answers to discuss whether it would be reasonable to conclude that the new anti-venom is effective at treating nonlethal scorpion stings in children. For the toolbar, press ALT+F10 (PC) or ALT+FN+F10 (Mac). TTTTParagraph Arial 3 (12pt) 三,三,T. 回i:公 E=E= = T T, U HTML CSS O Mashups

A medical researcher randomly assigns 100 high-risk heart patients into two groups. One group will get open heart surgery and the other groups will get a transcatheter aortic valve replacement. She will compare the two groups to see how long they live after their procedures. What statistical test should she use to analyze the data? a. Chi Square Goodness of Fit Test b. Correlation c. One sample t-test d. Independent Samples t-test e. Factorial ANOVA