An independent random sample is selected from an approximately normal population with unknown standard deviation. Find the degrees of freedom and the critical tvalue (t*) for the given sample size and condence level. (a) n = 7, CL = 90% degrees of freedom critical value (b) n = 24, CL = 98% degrees of freedom critical value (c) n = 34, CL = 95% degrees of freedom critical value (d) n = 14, CL = 99% degrees of freedom critical value An independent random sample is selected from an approximately normal population with an unknown standard deviation. Find the p-value for the given sample size and test statistic. (Assume we're considering a two sided hypothesis tests in each question. Round your answers to three decimal places.) (a) n = 11, T: 1.79 Determine if the null hypothesis would be rejected at a = 0.05. reject H0 fail to reject H0 (b) n = 17, T: 3.64 Determine if the null hypothesis would be rejected at at = 0.05. reject H0 fail to reject H0 (c) n = 7, T: 0.76 Determine if the null hypothesis would be rejected at a = 0.05. reject H0 fail to reject H0 (d) n = 28, T: 2.22 Determine if the null hypothesis would be rejected at a = 0.05. reject H0 fail to reject H0 Given a population that is approximately normal, find the following. (Use a table or technology. Round your answers to three decimal places.) USE SALT (a) Find the t critical value associated with 95% confidence with 5 df. = (b) Find the t critical value associated with 99% confidence with 15 df.Public health and safety officials have classied the Zika virus as a hazardous threat to pregnant women in Brazil. A study based in Rio found the virus to be more active near a body of water that was found to be polluted. A study of 20 water samples found an average chemical waste of 158 g per mile with a standard deviation of 17.46 g. u uses (a) What are the degrees of freedom for this study? (b) Find the 95% condence interval (in g per mile) for this study. (Use a table or technology. Round your answers to three decimal places.) ( , ) g per mile (c) What would happen to the margin of error if the sample size increased? It would also increase. 0 It would decrease. It would stay the same. It would go to zero. (d) What would happen to the margin of error if the confidence level increased? o It would also increase. It would decrease. It would stay the same. It would go to zero. The heights of young men are approximately normally distributed, with a mean of 69.8 inches. A random sample of heights from young men at a large university in the Midwest are listed below (in inches). 74 64 71 77,69 75 68 69 71 72 71 [A USES These data were used to calculate the sample mean and standard deviation. n= 11 2:71 s=3.5777 Is there sufcient evidence to say that the mean height for young men at the university is larger than average? (a) State the appropriate null and alternative hypotheses. H0: ,4 ? I69.8 Ha: ,4 2 .69.8 (b) Calculate the test statistic. (Round your answer to two decimal places.) t = (c) Based on a = 0.05, what is the correct conclusion for the hypothesis test? (Use a table or technology.) We would reject the null hypothesis. This means on the basis of the evidence, you can conclude the mean height of young men at the university is larger than 69.8 inches. We would fail to reject the null hypothesis. This means on the basis of the evidence, you can conclude that the mean height of young men at the university is larger than 69.8 inches. We would reject the null hypothesis. This means on the basis of the evidence, you cannot conclude the mean height of young men at the university is larger than 69.8 inches. 0 We would fail to reject the null hypothesis. This means on the basis of the evidence, you cannot conclude that the mean height of young men at the university is larger than 69.8 inches. The article \"Well-Fed Crickets Bowl Maidens Over"t reported that female eld crickets are attracted to males that have high chirp rates and hypothesized that chirp rate is related to nutritional status. The chirp rates for male eld crickets were reported to vary around a mean of 60 chirps per second. To investigate whether chirp rate is related to nutritional status, investigators fed male crickets a highprotein diet for 8 days and then measured chirp rate. The mean chirp rate for the crickets on the highprotein diet was reported to be 101 chirps per second. Is this convincing evidence that the mean chirp rate for crickets on a high-protein diet is greater than 60 (which would then imply an advantage in attracting the ladies)? Suppose that the sample size and sample standard deviation are n = 32 and s = 35. You can test the relevant hypotheses to answer this question. A significance level of a = 0.01 will be used. (a) State the null and alternative hypotheses. H0:,4=60 Ha:u*60 0H0:;4=60 Ha:;4>60 H0:;460 H0:;4=60 Ha:/4