A researcher is interested whether number of arrests vary across cities.  Two random samples were collected.  In city 1, the researcher sampled 185 individuals who had an average of 7.3 arrests with a standard deviation of 2.3 arrests.  In city 2, the researcher sampled 160 individuals who had an average of 8.2 arrests with a standard deviation of 2.4 arrests.  Test the null hypothesis at the .01 level of significance that the number of arrests does not vary across cities.  In so doing, identify: (1) the research and null hypothesis, (2) the critical value needed to reject the null, (3) the decision that you made upon analyzing the data, and (4) the conclusion you have drawn based on the decision you have made.

Do political sclence classes require more writing than history classes? The 57 randornly selected political science classes assigned an average of 17.8 pages of essay writing for the course. The standard deviation for these 57 classes was 4 pages. The 58 randomly selected history classes assigned an average of 16.8 pages of essay writing for the course. The standard devlation for these 58 classes was 5.6 pages. What can be concluded at the a = 0.10 level of significance? For this study, we should use Select an answer a. The null and alternative hypotheses would be: Ho: Select an answerv Select an answerv Select an answerv H: Select an answerv Select an answerv Select an answerv b. The test statistic ?v = (please show your answer to 3 decimal places.) c. The p-value = d. The p-value is ?v a e. Based on this, we should Select an answerv the null hypothesis. f. Thus, the final conclusion is that ... (Please show your answer to 4 decimal places.) O The results are statistically significant…

Dr. Graham is interested in determining if middle-aged adults use text messaging more or less frequently than the general population. Dr. Graham collects information on text messaging from a random sample of 50 adults ages 25 to 44. Dr. Graham finds that these individuals send or receive an average of 68 text messages per day. Using the population mean (and standard deviation) of 41.5 texts per day (34 texts per day), determine whether adults in this age group use text messaging more than the general public.

A college entrance exam company determined that a score of 21 on the mathematics portion of the exam suggests that a student is ready for college-level mathematics. To achieve this goal, the company recommends that students take a core curriculum of math courses in high school. Suppose a random sample of 200 students who completed this core set of courses results in a mean math score of 21.7 on the college entrance exam with a standard deviation of 3.4. Do these results suggest that students who complete the core curriculum are ready for college-level mathematics? That is, are they scoring above 21 on the mathematics portion of the exam? Complete parts a) through d) below. Click the icon to view the table of critical t-values. ... The/studentsyere randony ampled. eampleata ne froaopu lato that is approximately normal. le students test sc es were hdependetbhe another. F. None of he requirements are satişfied. ((c) Yse the P-value approach at the a = 0.10 level of significance to test…

Nationally, patients who go to the emergency room wait an average of 7 hours to be admitted into the hospital. Do patients at rural hospitals have a different waiting time? The 12 randomly selected patients who went to the emergency room at rural hospitals waited an average of 5.8 hours to be admitted into the hospital. The standard deviation for these 12 patients was 1.8 hours. What can be concluded at the a = 0.10 level of significance level of significance? a. For this study, we should use Select an answer b. The null and alternative hypotheses would be: Ho: ? Select an answer ✓ H₁: ?v Select an answer ✓ c. The test statistic ? ✓ (please show your answer to 3 decimal places.) (Please show your answer to 4 decimal places.) d. The p-value = e. The p-value is ? a f. Based on this, we should Select an answer the null hypothesis. g. Thus, the final conclusion is that ... O The data suggest that the population mean awaiting time to be admitted into the hospital from the emergency room for…

A college entrance exam company determined that a score of 21 on the mathematics portion of the exam suggests that a student is ready for college-level mathematics. To achieve this goal, the company recommends that students take a core curriculum of math courses in high school. Suppose a random sample of 250 students who completed this core set of courses results in a mean math score of 21.2 on the college entrance exam with a standard deviation of 3.3. Do these results suggest that students who complete the core curriculum are ready for college-level mathematics? That is, are they scoring above 21 on the math portion of the exam? Complete parts a) through d) below. iueiuiy uie LUSI SiauSuc. to = 0.96 (Round to two decimal places as needed.) Identify the P-value, P-value = (Round to three decimal places as needed.)

Two researchers conducted a study in which two groups of students were asked to answer 42 trivia questions from a board game. The students in group 1 were asked to spend 5 minutes thinking about what it would mean to be a professor, while the students in group 2 were asked to think about soccer hooligans. These pretest thoughts are a form of priming. The 200 students in group 1 had a mean score of 24.9 with a standard deviation of 4.3, while the 200 students in group 2 had a mean score of 17.2 with a standard deviation of 3.4. Complete parts (a) and (b) below. (a) Determine the 95% confidence interval for the difference in scores, µ, - H2. Interpret the interval. The lower bound is The upper bound is. (Round to three decimal places as needed.)

Two researchers conducted a study in which two groups of students were asked to answer 42 trivia questions from a board game. The students in group 1 were asked to spend 5 minutes thinking about what it would mean to be a​ professor, while the students in group 2 were asked to think about soccer hooligans. These pretest thoughts are a form of priming. The 200 students in group 1 had a mean score of 26.3 with a standard deviation of 5.2​, while the 200 students in group 2 had a mean score of 17.6 with a standard deviation of 2.8. Complete parts ​(a) and ​(b) below. ​(a) Determine the 90​% confidence interval for the difference in​ scores, μ1−μ2. Interpret the interval.   The lower bound is nothing. The upper bound is nothing. ​(Round to three decimal places as​ needed.)

In a study of computer use, 1000 randomly selected Canadian Internet users were asked how much time they spend using the Internet in a typical week. The mean of the sample observations was 12.8 hours. (a) The sample standard deviation was not reported, but suppose that it was 6 hours. Carry out a hypothesis test with a significance level of 0.05 to decide if there is convincing evidence that the mean time spent using the Internet by Canadians is greater than 12.6 hours. (Use a statistical computer package to calculate the P-value. Round your test statistic to two decimal places and your P-value to four decimal places.) t=P-value= State the conclusion in the problem context. Reject H0. We have convincing evidence that the mean weekly time spent using the Internet by Canadians is greater than 12.6 hours.Do not reject H0. We have convincing evidence that the mean weekly time spent using the Internet by Canadians is greater than 12.6 hours.    Reject H0. We do not have convincing…

An industrial plant wants to determine which of two types of fuel, electric or gas, is more cost efficient (measured in cost per unit of energy). Independent random samples were taken of plants using electricity and plants using gas. These samples consisted of  9  plants using electricity, which had a mean cost per unit of  $51.9  and standard deviation of  $7.98 , and  14  plants using gas, which had a mean of  $55.5  and standard deviation of  $8.73  . Assume that the populations of costs per unit are normally distributed for each type of fuel, and assume that the variances of these populations are equal. Can we conclude, at the  0.05  level of significance, that the mean cost per unit for plants using electricity,  μ1 , differs from the mean cost per unit for plants using gas,  μ2 ? Perform a two-tailed test. Then fill in the table below. Carry your intermediate computations to at least three decimal places and round your answers as specified in the table. (If…