A researcher wants to see if police officers’ enthusiasm for their jobs changes after having endured a horrific event (such as killing someone or being shot).  She tests a group of officers who have endured such an event and another group that has not on a measure of job satisfaction. What test should she run?  Is it one-tailed or two-tailed test?

▾ Part 1 of 4 John Paul teaches five sections of Introductory Psychology. He wants to know whether or not the average score on the second exam is the same for all five sections. John Paul's student's exam scores are listed below. Use an ANOVA test with a level of significance of 5% to test whether the average score is the same for all five sections. Section 1: 62, 76, 70, 66, 94, 59, 76, 65, 72, 79, 52, 46, 74, 43, 68, 61, 75, 65, 63, 58, 62, 76, 70, 61, 76, 73, 53, 57, 73, 78, 51, 54, 42, 66, 58, 72, 44, 87 Section 2: 65, 52, 51, 67, 64, 75, 56, 68, 72, 82, 74, 73, 83, 42, 73, 85, 67, 46, 70, 51, 72, 53, 28, 58, 62, 68, 58, 85, 71, 57, 60, 79, 64, 60, 69, 65, 66 Section 3: 83, 67, 69, 72, 67, 92, 57, 57, 57, 61, 90, 75, 62, 69, 50, 57, 60, 94, 83, 69, 68, 65, 81, 60, 81, 67, 72, 78, 79,65 Section 4: 63, 75, 55, 70, 75, 81, 50, 77, 59, 42, 44, 85, 57, 62, 33, 45, 82, 67, 68, 47, 75, 69, 48, 96, 79, 77 Section 5: 30, 82, 83, 54, 54, 59, 75, 43, 68, 58, 58, 45, 72, 67, 58, 82, 50, 63,…

Of the 328 patients that completed the survey last year, 211 of them claimed to be returning patients which is 64.3% of the sample. Is this an example of a retrospective, cross-sectional, or prospective observational study? Justify your answer.

Good credit: The Fair Isaac Corporation (FICO) credit score is used by banks and other lenders to determine whether someone is a good credit risk. Scores range from 300 to 850, with a score of 720 or more indicating that a person is a very good credit risk. An economist wants to determine whether the mean FICO score is more than the cutoff of 720. She finds that a random sample of 40 people had a mean FICO score of 760 with a standerd deviation of 95, Can the economist conclude that the mean FICO score is greater than 720? Use the a=0.01 level of significance and the P-value method with the T1-B4 Plus calculator. Part 1 of 4 State the appropriate null and altemate hypotheses. H D-0 H: This hypothesis test is a (Choose one) test. left-tailed right-tailed two-tailed

this is part 2 of a question. Although older Americans are most afraid of crime, it is young people who are more likely to be the actual victims of crime. It seems that older people are more cautious about the people with whom they associate. A national survey showed that 10% of all people ages 16-19 have been victims of crime.† At a high school, a random sample of n = 66 students (ages 16-19) showed that r = 11 had been victims of a crime. Note: For degrees of freedom d.f. not in the Student's t table, use the closest d.f. that is smaller. In some situations, this choice of d.f. may increase the P-value a small amount and thereby produce a slightly more "conservative" answer.   Find a 90% confidence interval for the proportion of students in this school (ages 16-19) who have been victims of a crime. (Round your answer to three decimal places.) lower limit       upper limit       (c) How large a sample size should be used to be 95% sure that the sample proportion p̂ is within…

As an admissions counselor, I am interested in understanding whether or not there is a difference in stress levels not only between different majors but also between different classes (Freshman v. Seniors). I gather the following data from students from three majors (Psychology, Chemistry, and Engineering), that are in their freshmen or senior years and ask them about their stress levels (scale of 1-10, with lower numbers meaning less stress). Using the data below, test whether there are effects of class, major, or an interaction between them at an alpha of 0.05.    Psychology Chemistry Engineering Freshmen 3, 4, 4, 2, 4 4, 5, 7, 8, 4 5, 7, 7, 8, 5 Senior 4, 5, 5, 3, 5 8, 5, 6, 7, 7 9, 9, 8, 7, 9 Complete the ANOVA summary table below:  Source SS df MS (variance) F MAJOR         CLASS         MAJOR*CLASS         ERROR/RESIDUAL       Nothing here TOTAL     Nothing here Nothing here   What can we conclude?…

In a study assessing helping behavior among college students on their way to class, you recruit 10 students. You tell some participants that they are late for class and need to rush. You tell others they are right on time. Finally, you tell others they have lots of time before class. As they walk across campus, they come across a man (actually a confederate) who appears to need help. You measure the extent to which the participant noticed that the confederate needed help (1 = did not notice to 9 = really noticed). What is the acceptable level of risk? P >.05 p <.05 P = .05 P <.1

You are a senior in the agricultural sciences department of NCSU doing an internship at a local dairy farm. Farmer Bill is an expert dairy farmer but has no background in quantitative decision making. Bill claims that the milk produced by his grass-fed Jersey cattle has higher protein content than the milk made by his grain-fed Jersey cattle. His evidence? He says he can taste the difference. You decide to put Bill's claim to the test. You randomly sample 21 grass-fed Jersey cattle and 18 grain-fed Jersey cattle, independently of one another, and obtain a sample of milk from each cow. Both histograms appear approximately normal. You test Ho : 4 = H2 VS. HA : H1 > 2. where 4 is the true mean protein content of milk produced by grass-fed Jersey cattle and-u, is that for the grain-fed cattle. Your test statistic is 1.98. Based on this information, which of the following is true ? Select one or more: O a. The sample mean protein content for the milk samples from the grass-fed cattle you…

A clinical psychologist is interested in the effect of a new treatment for treating depression. She randomly divides her clients into two groups. One group receives the new treatment and the other group receives the old treatment (control group).  At the end of treatment, she assesses the severity of their depression on a scale ranging from 0 to 20 (higher scores indicate greater depression). Was there a significant difference in depression scores between the two treatments?   New Treatment Old Treatment 2 7 5 10 3 6 8 8 11 4 4 8 6 10 4 4

A marketing agency wanted to determine if a new commercial changed people's opinion about a company. They recruited n=30 participants to watch the commercial. First, everyone was givien a survey to determine their attitudes toward the company. Then, everyone watched the new commercial. Finally, they were given the same survey again and asked about their attitudes toward the comapny after seeing the commercial. The agency wanted to see if attitudes were changed by the commercial. What statistical test should they use?