STA requires each student to train a rat to perform specific behaviors. Student grades are determined by the rats' performance. Mr. Simmons is concerned that students who have prior experience with training rats or other animals may have an advantage. To test the hypothesis, she gave each student a survey at the start of the class. The survey asked students about their previous animal related experiences. At the course's conclusion, she compared the rats' learning for students with prior animal experience to students without. Do the data suggest a significant difference between the two groups of students? Rat scores for students with animal Rat scores for students with no experience experience n = 15 M = 66 n = 10 M=78 SS = 1420 SS = 2030 State the hypotheses, critical values with df and alpha = .05, calculate the test statistic and show all your work for each step of the calculations, answer the question stated above in bold-italics, AND state your conclusion using the 3-sentence APA format discussed in class.

In an early study of the effects of frustration on feelings of hostility, Miller and Bugelski (1948) had a group of boys at a camp rate their attitudes toward two groups (Mexicans and Japanese). The campers then participated in a long, difficult, frustrating testing session that kept them away from their weekly movie. Finally the boys again rated their attitudes towards the minority groups. The scores below represent the number of unfavorable traits attributed to minorities and are similar to those of miller and Bugelski.    Participant   Before          After    A                  5                    6    B                  4                    4    C                  3                    5    D                  3                    4    E                  2                    4    F                  2                     3    G                 1                    3    H                 0                    2   a. Does the intervening unpleasant task alter attitudes toward the two…

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 wants to test the effectiveness of three new therapies that have been developed for reducing anxiety symptoms. The researcher recruits 15 participants and randomly assigns them to take part in Therapy A, Therapy B, or Therapy C for a month. At the end of the month, the researcher measures the participants' anxiety symptoms on a scale from 1 to 10 (where a higher score means more anxiety symptoms). The participants' scores are shown below: What is the appropriate test to use ? 3. What are the null and alternative hypotheses ? 4. Using a two-tailed alpha of .05, determine what the critical value is 5. Calculate the test statistic 6. State whether you reject or fail to reject the null hypothesis for the omnibus test 7. Calculate and report the effect size for the omnibus test 8. Perform a Post-Hoc Test. Report the significance of each pairwise comparison

Does the shape or color of a pain pill influence its effectiveness?  Although logically it shouldn’t, whether we believe a drug will work does have a powerful effect on our perceptions (e.g., placebo effect).  In this experiment, 4 groups of adult patients were given the same amount of Advil after dental surgery for pain relief, but the color and shape of the pill varied.  Researchers hypothesized that an unusual shape or color would lead people to believe the pills were new and special and thus would expect them to be more effective than common round, white pills. Researchers also wanted to know if there is an interaction between shape and color   what is the purpose and design of the study as well as the characteristics of the participants in the sample?

A report summarizing scores for students on a verbal aptitude test x and a math aptitude test y gives the following results: x = 480,  sx = 80,  y = 500,  sy = 120, r = 0.6.

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 group of statisticians decides they will answer the question:  Has the wolf reintroduction to Yellowstone been detrimental to elk herds in the park?  They decide that each of the four data scientists will take a quadrant of the park to collect a sample from as randomly as possible.  They decide they will collect the sample during the winter, the time the elk herds are most stressed.  They agree to trust each others professional judgement when it comes to the health of the individual elk in the herd.  They will give each elk a grade out of 3pts: 1 pt for sick, 2pts for fair, and 3pts for healthy.  They then share their data and compare to create a final report on the overall health of the elk in the park. In this scenario, what is the same for all samples (the control)?

A group of statisticians decides they will answer the question:  Has the wolf reintroduction to Yellowstone been detrimental to elk herds in the park?  They decide that each of the four data scientists will take a quadrant of the park to collect a sample from as randomly as possible.  They decide they will collect the sample during the winter, the time the elk herds are most stressed.  They agree to trust each others professional judgement when it comes to the health of the individual elk in the herd.  They will give each elk a grade out of 3pts: 1 pt for sick, 2pts for fair, and 3pts for healthy.  They then share their data and compare to create a final report on the overall health of the elk in the park. In this scenario, what is one of the factors that could negatively effect sample collection?

Brown wants to conduct an assessment of where employees live and how employees work. Brown wanted to know if where you lived was related to how you worked. What hypothesis tests can be used in this case?