Transtutors Week two. Use the APA format to support all the answers, with a minimum of 5 scholarly resources. Answer the first 8 questions On Key Concepts, from Jackson and Trochim, Donnelly, and Arora.The Title of the book is: Research Methods and Statistics: A Critical Thinking Approach 4th edition. Jackson even-numbered Chapter exercises (Chapter 8 pp. 220-221; Chapter 10 pp 273-275). 1. The producers of a new toothpaste claim that it prevents more cavities than other brads of toothpaste. A random Sample of 60 people used the new toothpaste for 6 months. The mean number of cavities at their next checkup is 1.5. In the general population, the mean number of cavities at a 6 month check up is 1.73 (& = 1.2). a) Is this a one-or two tailed tests? b) What are Ho and Ha for this study? c) Compute Z obt d) What is Z ev? 2. Henry performed a two – tailed test for an experiment in which N=24. He could not fine his table of t critical values, but remembered what the t cv at df = 13. He decided to compare his t obt with this t cv. Is he more likely to make a type I or type II error in this situation? 3. A researcher hypothesizes that individuals who listen to classical music will score differently from the general population on a test of special ability. On a standardized test of spatial ability U= 58. A random sample of 14 individuals who listen to classical music is given the same test. Their scores on the test are 52, 59, 63, 65, 58, 55, 62, 63, 53, 59, 57, 61, 60, 59. a) Is this a one-or two tailed test? b) What are Ho and Ha for this study? c) Compute t obt d) What is t ev? e) Should Ho be rejected? What should the researcher conclude? f) Determine the 98% confidence interval for the population mean, based on the sample mean. 4. A researcher believes that the percentage of people who exercise in California is greater than the national exercise rate. The national rate is 20%. The researcher gathers a random sample of 120 individuals who live in California and finds that the number who exercise regularly is 31 out of 120. a) What is X squared obt? b) What is df for this test? c) What is X squared cv? d) What conclusion should be drawn from these results? 5. A student is interested in whether students who study with music playing devote as much attention to their studies as do students who study under quiet conditions ( he believes that studying under quiet conditions leads to better attention). He randomly assigns participants to either the music or no-music condition and has them ready and study the same passage of information for the same amount of time. Subjects are given the same 10 -item test on the material. Their scores appear next. Scores on the test represent interval -ration data and are normally distributed. Music: 6, 5, 6, 5, 6, 6, 7, 8, 5. No Music: 10, 9, 7, 7, 6, 6, 8, 6, 9, a) What statistical test should be used to analyze these data? b) Identify Ho and Ha for this study. c) Conduct the appropriate analysis. d) Should Ho be rejected? What should the researcher conclude? e) If significant, compute and interpret the effect size. f) If significant, draw a graph representing the data. g) Determine the 95% confidence interval. 6. The researcher in the above exercise decides to conduct the same study using a within-participants design to control for differences in cognitive ability. He selects a random sample of subjects and has them study different material of equal difficulty in both the music and no music conditions. The study is completely counterbalanced to control for order effects. The data appear next. As before, they are measured on an interval -ration scale and are normally distributed; he believes that studying under quiet conditions will lead to better performance. Music: 7,6, 5, 6, 8, 8. No Music: 7, 8, 7, 7, 9, 8. a) What statistical test should be used to analyze these data? b) Identify Ho and Ha for this study. c) Conduct the appropriate analysis. d) Should Ho be rejected? What should the researcher conclude? e) If significant, compute and interpret the effect size. 7. Researchers at a food company are interested in how a new spaghetti sauce made from green tomatoes (and green in color) will compare to their traditional red spaghetti sauce. They are worried that the green color will adversely affect the tastiness scores. They randomly assign subjects to either the green or red sauce condition. Participants indicate the tastiness of the sauce on a 10-point scale. Tastiness scores tend to be skewed. The scores follow. Red Sauce: 7, 6, 9, 10, 6, 7, 8. Green Sauce: 4, 5, 6, 8, 7, 6, 9. a) What statistical test should be used to analyze this data? b) Identify Ho and Ha for this study. 8. You notice in your introductory psychology class that more women tend to sit up front, and more men sit in the back. To determine whether this difference is significant, you collect data on the seating preferences for the student in your class. The data follow. Front of the room: Men 15, Women 27. Back of the room: Men 32, Women 19. a) What is X squared obt? b) What is df for this test? c) What is X squared cv? d) What conclusion should be drawn from these studies? 9. What are degrees of freedom? How are the calculated? 10.What do inferential statistics allow you to infer? 11.What is the General Linear Model (GLM)? Why does it matter? 12.Compare and contrast parametric and nonparametric statistics. Why and in what types of cases would you use one over the other? 13.Why is it important to pay attention to the assumptions of the statistical test? What are your options if your dependent variable scores are not normally distributed? 14.What does p = .05 mean? What are some misconceptions about the meaning of p =.05? 15.Why are they wrong? Should all research adhere to the p = .05 standard for significance? Why or why not? 16.Compare and contrast the concepts of effect size and statistical significance. 17.What is the difference between a statistically significant result and a clinically or “real world” significant result? Give examples of both. 18.What is NHST? Describe the assumptions of the model. 19.Describe and explain three criticisms of NHST. 20.Describe and explain two alternatives to NHST. What do their proponents consider to be their advantages?