In randomized, double-blind clinical trials of a new vaccine, monkeys were randomly divided into two groups. Subjects in group 1 received the new vaccine while subjects in group 2 received a control vaccine. After the second dose, 117 of 750 subjects in the experimental group (group 1) experienced drowsiness as a side effect. After the second dose, 74 of 631 of the subjects in the control group (group 2) experienced drowsiness as a side effect. Does the evidence suggest that a higher proportion of subjects in group 1 experienced drowsiness as a side effect than subjects in group 2 at the a = 0.05 level of significance? Determine the P-value for this hypothesis test. (Round to three decimal places as needed.) Interpret the P-value. If the population proportions are one would expect a sample difference proportion V the one observed in about out of 1000 repetitions of this experiment. (Round to the nearest integer as needed.) State the conclusion for this hypothesis test. O A. Reject Ho. There is sufficient evidence to conclude that a higher proportion of subjects in group 1 experienced drowsiness as a side effect than subjects in group 2 at the a = 0.05 level of significance. O B. Do not reject Ho. There is not sufficient evidence to conclude that a higher proportion of subjects in group 1 experienced drowsiness as a side effect than subjects in group 2 at the a = 0.05 level of significance. O C. Reject Ho. There is not sufficient evidence to conclude that a higher proportion of subjects in 1 experienced drowsiness as a side effect than subjects in group 2 at the a = 0.05 level of significance. O D. Do not reject Ho. There is sufficient evidence to conclude that a higher proportion of subjects in group 1 experienced drowsiness as a side effect than subjects in group 2 at the a = 0.05 level of significance.

A study used 1259 patients who had suffered a stroke. The study randomly assigned each subject to an aspirin treatment or a placebo treatment. During a 3-year follow-up period, in Sample 1, 634 people received placebo treatments and 25 people died from heart attack. In sample 2, 625 people received aspirin treatment and 18 died from heart attack. Let pl denote the population proportion of death from heart attack for those with no treatment and p2 denote the population proportion of death from heart attack for those with aspirin treatment. (c) Which of SEO and SE1 is used for calculating a confidence interval for comparing two population proportions? Which is used for calculating the test statistic in a hypothesis test? (d) Construct the 95% confidence interval for pi – p2. Interpret.

How many subjects in the "patch only" group would you expect not to quit

A large clinical trial of the effect of diet on breast cancer assigned women at random to either a normal diet or a low-fat diet. To check that the random assignment did produce comparable groups, we can compare the two groups at the start of the study. Asked if there is a family history of breast cancer: 1276 of the 5964 women in the low-fat group and 1507 of the 7726 women in the control group said "Yes." If the random assignment worked well, there should not be a significant difference in the proportions with a family history of breast cancer. How significant is the observed difference? State: Is there evidence of a difference in the proportion of women with a family history of breast cancer between the treatment and control groups? Plan: Let pi be the proportion for the treatment group, and Pz the proportion for the control group. State the hypotheses for your test. Ha:Pi + P2 Solve: Give the value of the test statistic. Use the calculator. Select an answer ♥ Ho:pi = p2 What is the…

In randomized, double-blind clinical trials of a new vaccine, children were randomly divided into two groups. Subjects in group 1 received the new vaccine while subjects in group 2 received a control vaccine. After the second dose, 125 of 746 subjects in the experimental group (group 1) experienced fever as a side effect. After the second dose, 82 of 627 of the subjects in the control group (group 2) experienced fever as a side effect. Does the evidence suggest that a higher proportion of subjects in group 1 experienced fever as a side effect than subjects in group 2 at the a= 0.01 level of significance? Find the test statistic for this hypothesis test. (Round to two decimal places as needed.)

A clinical trial is conducted to compare an experimental medication to placebo to reduce the symptoms of asthma. Two hundred participants are enrolled in the study and randomized to receive either the experimental medication or placebo. The primary outcome is self-reported reduction of symptoms. Among 100 participants who receive the experimental medication, 38 report a reduction of symptoms as compared to 21 participants of 100 assigned to placebo. When you test if there is a significant difference in the proportions of participants reporting a reduction of symptoms between the experimental and placebo groups. Use α = 0.05. What should the researcher’s conclusion be for a 5% significance level? Reject H0because 2.64 ≥ 1.960. We have statistically significant evidence at α = 0.05 to show that there is a difference in the proportions of patients reporting a reduction in symptoms.     We reject H0 at the 5% level because 2.64 is greater than 1.96. We do have statistically…

Acne is a common skin disease that affects most adolescents and can continue into adulthood. A study compared the effectiveness of three acne treatments and a placebo, all in gel form, applied twice daily for 12 weeks. The study's 517 teenage volunteers were randomly assigned to one of the four treatments. Success was assessed as clear or almost clear skin at the end of the 12 week period. The results of the study can be seen in the table below. Using the appropriate statistical test, determine if there is significant evidence that the four treatments perform differently. If so, how do they compare.

A clinical trial is conducted to compare an experimental medication to placebo to reduce the symptoms of asthma. Two hundred participants are enrolled in the study and randomized to receive either the experimental medication or placebo. The primary outcome is self-reported reduction of symptoms. Among 100 participants who receive the experimental medication, 38 report a reduction of symptoms as compared to 21 participants of 100 assigned to placebo. When you test if there is a significant difference in the proportions of participants reporting a reduction of symptoms between the experimental and placebo groups. Use α = 0.05. What should the researcher’s conclusion be for a 5% significance level? Reject H0because 2.64 ≥ 1.960. We have statistically significant evidence at α = 0.05 to show that there is a difference in the proportions of patients reporting a reduction in symptoms.     We reject H0 at the 5% level because 2.64 is greater than 1.96. We do have statistically…

A clinical trial is conducted to compare an experimental medication to placebo to reduce the symptoms of asthma. Two hundred participants are enrolled in the study and randomized to receive either the experimental medication or placebo. The primary outcome is self-reported reduction of symptoms. Among 100 participants who receive the experimental medication, 38 report a reduction of symptoms as compared to 21 participants of 100 assigned to placebo. When you test if there is a significant difference in the proportions of participants reporting a reduction of symptoms between the experimental and placebo groups. Use α = 0.05. What should the researcher’s conclusion be for a 5% significance level? Reject H0because 2.64 ≥ 1.960. We have statistically significant evidence at α = 0.05 to show that there is a difference in the proportions of patients reporting a reduction in symptoms.     We reject H0 at the 5% level because 2.64 is greater than 1.96. We do have statistically…

In randomized, double-blind clinical trials of a new vaccine, children were randomly divided into two groups. Subjects in group 1 received the new vaccine while subjects in group 2 received a control vaccine. After the second dose, 123 of 460 subjects in the experimental group (group 1) experienced drowsiness as a side effect. After the second dose, 24 of 106 of the subjects in the control group (group 2) experienced drowsiness as a side effect. Does the evidence suggest that a different proportion of subjects in group 1 experienced drowsiness as a side effect than subjects in group 2 at the a = 0.01 level of significance? Determine the null and alternative hypotheses. Choose the correct answer below. A. Ho: P1 =0 versus Ho: P, #0 B. Ho: P =P2 versus H,: P, P2 The test statistic zo is (Round to two decimal places as needed.)