Before you begin this discussion, find a coin and flip it 10 times, recording the outcome of each flip as either heads or tails. Post your results in this discussion, along with the percentage of flips that resulted in heads. We might expect that percentage to be 50%, but the results may vary from student to student (sometimes drastically) in this exercise. As a response to other students, add their data to yours and compute the new percentage of flips that result in heads (You can just make up realistic predictions for the other students). With enough data added, what would you expect to find? What does the central limit theorem have to say about the long-term outcome of exercises like this?

The makers of the Oral-B 3D toothbrush claims that using their brush will "significantly combat tooth decay" when compared with regular toothbrushes. College students have an average of 0.70 (s = 0.40) cavities filled in a given year. You randomly ask 100 students to use the Oral-B 3D toothbrush for one year. They have an average of 0.631 cavities filled in that year. Does the Oral-B 3D toothbrush combat tooth decay at a significance level of .05? Complete a hypothesis test of this study that the using the Oral-B 3D toothbrush reduces (e.g., a "directional" hypothesis) tooth decay. Be sure to include all six steps of a hypothesis test.

USE Z Test.

Grade point average, fraternities, sororities, and two-way between-groups ANOVA: A sample of students from our statistics classes reported their GPAs, indicated their genders, and stated whether they were in the university’s Greek system (i.e., in a fraternity or sorority). Following are the GPAs for the different groups of students: Men in a fraternity: 2.6, 2.4, 2.9, 3.0 Men not in a fraternity: 3.0, 2.9, 3.4, 3.7, 3.0 Women in a sorority: 3.1, 3.0, 3.2, 2.9 Women not in a sorority: 3.4, 3.0, 3.1, 3.1 What are the independent variables and their levels? What is the dependent variable? Draw a table that lists the cells of the study design. Include the cell means. Conduct all six steps of hypothesis testing.

Decisions about alpha level may be different, especially as it relates from hard sciences to social sciences. For example, a medical trial for cancer treatments conducts their statistical tests at .0001 – so for every 1 out of 10,000 patients, there may be issues, sickness or even death. For social science, we use alpha .05. We are comfortable with performing research, for example, on students. So we are satisfied with losing 5 out of 100 students or having our results being incorrect 5 out of 100 times. Do you agree with these alpha levels? Why or why not? What if your child’s education and the teacher assigned to him/her would be successful 95 out of 100 times?

z scores are useful for A) finding the average B) measuring distance C) comparing scores on different scales D) none of the above

Kurtosis refers to a distribution that is negatively skewed. True or false

The following is an example of a null hypothesis: People who eat dinner after 6 PM weigh more than people who do not eat after 6 PM. True or False

The following is an example of a directional hypothesis: Students who spend more hours studying get higher grades than students who spend less hours studying. True or False

If a researcher concludes that a variable has an effect when it really doesnt, the research has made what type of error?

Decisions about alpha level may be different, especially as it relates from hard sciences to social sciences. For example, a medical trial for cancer treatments conducts their statistical tests at .0001 – so for every 1 out of 10,000 patients, there may be issues, sickness or even death. For social science, we use alpha .05. We are comfortable with performing research, for example, on students. So we are satisfied with losing 5 out of 100 students or having our results being incorrect 5 out of 100 times. Do you agree with these alpha levels? Why or why not? What if your child’s education and the teacher assigned to him/her would be successful 95 out of 100 times?

Right versus left. The design of controls and instruments affects how easily people can use them. Timothy Sturm investigated this effect in a course project, asking 25 right-handed students to turn a knob (with their right hands) that moved an indicator by screw action. There were two identical instruments: one with a right-hand thread (the knob turns clockwise), and the other with a left-hand thread (the knob turns counterclockwise). Table 20.4 gives the times in seconds each subject took to move the indicator a fixed distance.33 DATA RTLFT

(a) Each of the 25 students used both instruments. Explain briefly how you would use randomization in arranging the experiment.

The price of a certain combo meal at different franchises of a national fast food company varies from​ $5.00 to ​$17.37and has a known standard deviation of

$2.09. A sample of 29students in an online course that includes students across the country stated that their average price is $6.00.

The students have also stated that they are generally unwilling to pay more than $6.75 for this meal. Formulate and conduct a hypothesis test to determine if you can conclude that the population mean is less than $6.75.

Use a level of significance of 0.05.

Is there sufficient evidence at the 0.05 level of significance that the population mean is less than ​$6.75​?

Determine the null​ hypothesis, H0​,and the alternative​ hypothesis, H1.

compute test statistic

find the pvalue

state the conclusion

Tracy is in her last semester of nursing school where she is taking a course in which her class learns about the importance of evidence-based practice. Dr. Minturn, the nursing professor who teaches the course, has asked the students to write a paper about a mock research study of their choosing. The students are to pose a clinical question and then map how they would create a research study around the question. They are not to actually carry out the research, but they are to envision what their study would look like and then map it on paper.

1. Tracy needs to conduct a literature review of her chosen phenomena of study. One database she can use to obtain peer reviewed nursing articles is:

In an experiment to determine the effect of nutrition on the attention spans of elementary school students, a group of 45 students is divided into three groups of 15, and randomly assigned to each of three meal plans: no breakfast, light breakfast, and full breakfast. Their attention spans, in minutes, were recorded. Say you want to test the hypothesis that the means of the attention spans are not all the same at a level of significance of 5%.

(a) (3 pts) What are the null and alternative hypotheses?

(b) (4 pts) Suppose that you find MSG=26 and MSE=3.1. Find the F-statistic, and estimate the p-value of your data using the F-table.

(c) (3 pts) Should you accept or reject? Explain.