34. A clinical trial was conducted using a new method designed to increase the probability of conceiving a girl. As of this writing, 946 babies were born to parents using the new method, and 868 of them were girls. Use a 0.05 significance level to test the claim that the new method is effective in increasing the likelihood that a baby will be a girl. Identify the null hypothesis, alternative hypothesis, test statistic, P-value, conclusion about the null hypothesis, and final conclusion that addresses the original claim. Use the P-value method and the normal distribution as an approximation to the binomial distribution.
(a) What is the hypothesis test to be conducted?
(b) What is the test statistic?
(c) What is the P-value?
(d) What is the conclusion about the null hypothesis?
(e) What is the final conclusion?
36. In a study of 420,138 cell phone users, 106 subjects developed cancer of the brain or nervous system. Test the claim of a somewhat common belief that such cancers are affected by cell phone use. That is, test the claim that cell phone users develop cancer of the brain or nervous system at a rate that is different from the rate of 0.0340% for people who do not use cell phones. Because this issue has such great importance, use a 0.005 significance level. Identify the null hypothesis, alternative hypothesis, test statistic, P-value, conclusion about the null hypothesis, and final conclusion that addresses the original claim. Use the P-value method and the normal distribution as an approximation to the binomial distribution.
(a) What is the hypothesis test to be conducted?
(b) What is the test statistic?
(c) What is the P-value?
(d) What is the conclusion about the null hypothesis?
(e) What is the final conclusion?
37. Trials in an experiment with a polygraph include 99 results that include 23 cases of wrong results and 76 cases of correct results. Use a 0.01 significance level to test the claim that such polygraph results are correct less than 80% of the time. Identify the null hypothesis, alternative hypothesis, test statistic, P-value, conclusion about the null hypothesis, and final conclusion that addresses the original claim. Use the P-value method. Use the normal distribution as an approximation of the binomial distribution.
(a) Let p be the population proportion of correct polygraph results. What is the null and alternative hypotheses?
(b) Identify the level of significance α?
(c) What is the test statistic?
(d) What is the p-value?
(e) Determine if the test is left-tailed, right-tailed, or two-tailed.