What is the primary purpose of inferential statistics?

  
MODULE 2
A
How is sample size related to statistical tests and outcomes? Give a specific example. Why is it important to plan the sample size before collecting data?
B
Fill in the following for a possible study with one independent variable (IV) with two conditions/treatments and a dependent variable (DV) that is measured on a continuous scale (interval or ratio):
·  Independent variable = ______________
· Condition A = ______________
· Condition B = ______________
· Dependent variable = _______________
· How do you know this DV is measured on a continuous scale?
· How would you word the null hypothesis for your sample study?
· How would you word the alternative hypothesis for your sample study?
· What alpha level would you set to test your hypothesis? Why?

MODULE 3
A
What is the primary purpose of inferential statistics? How might inferential statistics be applied to your intended research study? Explain.

Researchers often assume a normal distribution of data. Why is this significant in quantitative research? Explain.

MODULE 4
A
Mary is planning a study to see if learning of 6th graders on a math lesson is affected by background noise level. She wants to use a t-test for independent groups to analyze her results. Help her plan her study. What is her independent variable (IV) here? Describe two conditions she could create for the IV in her study. What is her dependent variable (DV) here? Describe a way to measure the DV so that each participant would have one score at the end. Would this DV measure be on a continuous scale of measurement? Why is this important? Explain and justify.
B
Consider Mary’s experiment regarding whether learning of 6th graders on a math lesson is affected by background noise level. Mary has collected her data. What is the null hypothesis for her study? What is the alternative hypothesis for her study? What are the assumptions that must be met about her data before she can correctly use an independent t-test to test the hypotheses? Why? How would she see if her data met these assumptions? How much room does she have to violate any of these assumptions and still get accurate results from the t-test? Explain and support your answers.

MODULE 5
A
In Module 4, we considered Mary’s interest in doing a study to see if learning of 6th graders on a math lesson is affected by background noise level. There, she was planning to use two noise conditions and then analyze her outcomes using a t-test for independent groups. Describe the study Mary might plan where she would use a one-way analysis of variance (ANOVA) for independent groups instead of a t-test to study differences between noise levels. What is her independent variable here? Describe the conditions she could create for this study. What is her dependent variable? Describe a way to measure the DV so that each participant would have one score at the end that would be on a continuous scale of measurement. Support your responses.
B
Consider Mary’s study of whether the learning of 6th graders on a math lesson is affected by background noise level. Describe the pros and cons of Mary using a repeated measures design for this study. What would you probably choose to do? Support your responses.

Ethics in Epidemiological Research.

 
Ethics in Epidemiological Research
An Experimental Study in the Primary Prevention of Type 2 Diabetes
Imagine that researchers are conducting a randomized controlled trial of a high-fiber supplement as a preventive measure in persons at increased risk of type 2 diabetes. People enrolled in the study are disease-free at the time they agree to participate in the trial, but they all have a family history of type 2 diabetes and are considered at high-risk (80%) to develop the disease during their lifetime. The 10,000 participants who start the trial are healthy individuals who are randomly allocated to receive either high-fiber supplements or placebo for several years. As you can imagine, this study will be quite expensive and will require a large infrastructure of personnel and materials to carry it out successfully.
Because type 2 diabetes has reached epidemic proportions in the United States, the potential benefits of this research are important at a population level. Unfortunately, high-fiber supplements have also been shown in a few studies to be associated with gastrointestinal blockage (which can be life-threatening) and reduced nutrient absorption, which may lead to anemia, osteoporosis, and other debilitating chronic diseases. The supplements may also reduce absorption of certain medications and cause gastrointestinal distress. The potential side effects of continuous high-fiber supplementation are only partially understood, and long-term effects are unknown.
By Day 8
Post your initial response to at least two of the following questions:

What are the potential risks and benefits to be considered when designing this study?
When the side effects and long-term effects of a potential preventive measure are largely unknown, is it ethical to expose participants to these risks? Why or why not?
Is it ethical to deny the possible prevention benefits of high-fiber supplements to persons in the placebo group? Why or why not?
Do the potential benefits outweigh the potential risks to the participants and to society? Why or why not?

The differences among the types of epidemiological study designs is important for translating the results to public health practice.

 
Epidemiological Study Designs
Understanding the differences among the types of epidemiological study designs is important for translating the results to public health practice. For this Discussion, you will identify and design epidemiological research studies. To prepare, review the Learning Resources about epidemiologic study designs. Then, go to the Walden Library or another scholarly library and find an epidemiological research study that was published in the last 3 months and uses one of the study designs we are learning about in this module.
– Briefly summarize the study in your own words, identify the study design it uses, and discuss what features it has that identify it as that type of study design. Do not just copy the abstract or parts of the article. Then, redesign the same study using a different study design than the authors did. This does not mean finding another article on the topic. Instead, pretend you are the epidemiologist and design your own study on the topic, using the information we’ve been learning in class about study designs, exposures, outcomes, and measures of association. You are the researcher! For the study you are designing, be sure to include information on who the participants would be and how you would measure the exposure and outcome variables. Discuss why your study design is stronger or more limited than the original study design, and how you arrived at this conclusion. Finally, pose a question about study designs to your peers that is based on your post.

Criminal Justice agencies often gather large quantities of variables to be used in descriptive analyses.

500-700 words 3 references 

Criminal Justice agencies often gather large quantities of variables to be used in descriptive analyses. That is, to help describe situations, populations, and so on. For instance, the Department of Corrections collects data on inmates. Variables often include crime type, race, gender, originating jurisdiction (where they were convicted), education level, and many others. 
These data are often captured categorically rather than numerically. For instance, education level might be captured by simply identifying the name of the highest grade an offender achieved, such as high school diploma or GED, Bachelor’s degree, Associates degree, and so forth. Similarly, race data are most often captured by recording the label of the race the offender belongs to, such as Caucasian, African American, Asian, Native American, Pacific Islander, and so on. These labels have no inherent numerical value because they are simply categories. Thus, they are categorical variables. 
You cannot use traditional statistical analysis to investigate relationships between categorical variables because they are not numbers. Instead, you would use nonparametric tests, such as the chi-square test of independence. You will use this test to investigate the data below. 
This assignment has 2 steps. 
Step 1: Watch both of the following videos regarding chi-square analysis: 

Filling Out Frequency Table for Independent Events 
Contingency Table Chi-Square Test

Step 2: Calculate chi-square using the data in the table below, this Chi Square Example Handout, and the Distribution Values Chart that go with this IP. 
Using the Chi-Square Example Handout and the Chi-Square Distribution Values Chart as guides to figure the calculations, calculate chi-square for the following data:
 
 Originating Jurisdiction              Caucasian               African American  
Denver County                                        16                                             3  
El Paso County                                           4                                              6  
Pueblo County                                           6                                             15 

Then, answer the following questions about your results:

What is the column total for Caucasian?  
What is the column total for African American?   
What is the row total for Denver County?  
What is the row total for El Paso County?   
What is the row total for Pueblo County?  
Are race and originating jurisdiction significantly dependent? How do you know?   
What is the final chi-square value?  
How many degrees of freedom are there for this chi-square table?   
What is the value for the 0.05 significance level and 2 degrees of freedom on the Chi-Square Distribution Values Chart?   
Do you reject or accept the null hypothesis that states, “Originating Jurisdiction and Race are not significantly dependent (they are independent)”?

For assistance with your assignment, please use your text, Web resources, and all course materials.

References

Khan Academy. (2017a). Contingency table chi-square test [Video file]. Retrieved from https://www.khanacademy.org/math/statistics-probability/inference-categorical-data-chi-square-tests/chi-square-tests-for-homogeneity-and-association-independence/v/contingency-table-chi-square-test

Khan Academy. (2017b). Filling out frequency table for independent events [Video file]. Retrieved from https://www.khanacademy.org/math/statistics-probability/inference-categorical-data-chi-square-tests/chi-square-tests-for-homogeneity-and-association-independence/v/frequency-table-independent-events

The purpose of this assignment is for students to learn how to use Microsoft Excel®for solving formulas.

Purpose of Assignment 
The purpose of this assignment is for students to learn how to use Microsoft Excel®for solving formulas. Managers and staff need to work with percentages daily in professional settings. Skills such as finding the percentage increase/decrease and using Excel®to convert from decimals to percentages and vice versa have become necessary. This assignment provides students with the practice of such fundamental quantitative concepts. 
Assignment Steps 
Resources: Fundamental Quantitative Concepts Exercises Excel®Template 
Savethe Fundamental Quantitative Concepts Exercises Excel® Template to your computer.
Readthe instructions on the first tab.
Completethe ten Excel®exercises.

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