Answer the following questions:
1. The producers of a new toothpaste claim that it prevents more cavities than other brands 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 checkup is 1.73 (‘ = 1.12).
a. Is this a one- or two-tailed test?
b. What are H0 and Ha for this study?
c. Compute zobt.
d. What is zcv?
e. Should H0 be rejected? What should the researcher conclude?
f. Determine the 95% confidence interval for the population mean, based on the sample mean
2. Henry performed a two-tailed test for an experiment in which N = 24. He could not find his table of t critical values, but he remembered the tcv at df = 13. He decided to compare his tobt with this tcv. 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 spatial ability. On a standardized test of spatial ability, ” = 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 H0 and Ha for this study?
c. Compute tobt.
d. What is tcv?
e. Should H0 be rejected? What should the researcher conclude?
f. Determine the 95% 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 then 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 120.
a. What is x2obt?
b. What is df for this test?
c. What is x2cv?
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 read 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 score appears next. Scores on
1. What are degrees of freedom? How are the calculated?
2. What do inferential statistics allow you to infer?
3. What is the General Linear Model (GLM)? Why does it matter?
4. Compare and contrast parametric and nonparametric statistics. Why and in what types of cases would you use one over the other?
5. 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?
Part II
Part II introduces you to a debate in the field of education between those who support Null Hypothesis Significance Testing (NHST) and those who argue that NHST is poorly suited to most of the questions educators are interested in. But, as the authors of the readings for Part II argue, using statistical analyses based on this model may yield very misleading results. You may or may not propose a study that uses alternative models of data analysis and presentation of findings (e.g., confidence intervals and effect sizes) or supplements NHST with another model. In any case, by learning about alternatives to NHST, you will better understand it and the culture of the field of education.
Answer the following questions:
1. What does p = .05 mean? What are some misconceptions about the meaning of p =.05? Why are they wrong? Should all research adhere to the p = .05 standard for significance? Why or why not?
2. Compare and contrast the concepts of effect size and stathttp://usaonlineessays.com/wp-admin/post-new.phpistical significance.
3. What is the difference between a statistically significant result and a clinically or “real world” significant result? Give examples of both.
4. What is NHST? Describe the assumptions of the model.
5. Describe and explain three criticisms of NHST.
6. Describe and explain two alternatives to NHST. What do their proponents consider to be their advantages?
7. Which type of analysis would best answer the research question you stated in Activity 1? Justify your answer.
Support your paper with a minimum of 5 resources. In addition to these specified resources, other appropriate scholarly resources, including older articles, may be included.
Length: 5-7 pages not including title and reference pages
References: Minimum of 5 scholarly resources.
Your paper should demonstrate thoughtful consideration of the ideas and concepts that are presented in the course and provide new thoughts and insights relating directly to this topic. Your paper should reflect scholarly writing and current APA standards. Review APA Form and Style.