Stat 171 Elementary StatisticsComputer Project #1In this project, each student will design a sample survey that should consist of only two
questions. Students can choose his/her research interest and collect data from those
interested topics. The survey questions should consist of two types of data: a quantitative
data question (numerical response) and a qualitative data question (categorical
responses). The sample size should be around n=25 people/objects. Please also write the
type of sampling technique used in the study in a paragraph. You may use a convenience
sample or voluntary response sample or more advanced simple random sample (SRS) in
selecting observations for your sample

MODULE 3: AVERAGES, VARIATION, AND PROBABILITY THEORY ASSIGNMENT Questions are taken directly from Brase, Brase, Dolor, and Seibert Chapters 3 and 4, pages 126 and 179. In case an eBook page number differs, the questions are listed below: Discuss each of the following topics in class or review the topics on your own. Then, write a brief but complete essay in which you summarize the main points. Please include formulas and graphs as appropriate. Chapter 3: 1. An average is an attempt to summarize a collection of data into just one number. Discuss how the mean, median, and mode all represent averages in this context. Also, discuss the differences among these averages. Why is the mean a balance point? Why is the median a midway point? Why is the mode the most common data point? List three areas of daily life in which you think the mean, median, or mode would be the best choice to describe an average. 2. Why do we need to study the variation of a collection of data? Why isnt the average by itself adequate? We have studied three ways to measure variation. The range, the standard deviation, and, to a large extent, a box-and-whisker plot all indicate the variation within a data collection. Discuss similarities and differences among these ways to measure data variation. Why would it seem reasonable to pair the median with a box-and-whisker plot and to pair the mean with the standard deviation? What are the advantages and disadvantages of each method of describing data spread? Comment on statements such as the following: a. The range is easy to compute, but it doesnt give much information; b. although the standard deviation is more complicated to compute, it has some significant applications; c. the box-and-whisker plot is fairly easy to construct, and it gives a lot of information at a glance. 3. Why is the coefficient of variation important? What do we mean when we say that the coefficient of variation has no units? What advantage can there be in having no units? Why is relative size important? Consider robin eggs; the mean weight of a collection of robin eggs is 0.72 ounces, and the standard deviation is 0.12 ounces. Now consider elephants; the mean weight of elephants in the zoo is 6.42 tons, with a standard deviation of 1.07 tons. The units of measurement are different, and there is a great deal of difference between the weight of an elephant and that of a robins egg. Yet the coefficient of variation is about the same for both. Comment on this from the viewpoint of the size of the standard deviation relative to that of the mean. 4. What is Chebyshevs theorem? Suppose you have a friend who knows very little about statistics. Write a paragraph or two in which you describe Chebyshevs theorem for your friend. Keep the discussion as simple as possible, but be sure to get the main ideas across to your friend. Suppose they ask, What is this stuff good for? and suppose you respond (a little sarcastically) that Chebyshevs theorem applies to everything from butterflies to the orbits of the planets! Would you be correct? Explain. Chapter 4 1. Discuss the following concepts and give examples from everyday life in which you might encounter each concept. Hint: For instance, consider the experiment of arriving for class. Some possible outcomes are not arriving (that is, missing class), arriving on time, and arriving late. a. Sample space. b. Probability assignment to a sample space. In your discussion, be sure to include answers to the following questions. i. Is there more than one valid way to assign probabilities to a sample space? Explain and give an example. ii. How can probabilities be estimated by relative frequencies? How can probabilities be computed if events are equally likely? 2. Discuss the concepts of mutually exclusive events and independent events. List several examples of each type of event from everyday life. a. If AA and BB are mutually exclusive events, does it follow that AA and BB cannot be independent events? Give an example to demonstrate your answer. Hint: Discuss an election where only one person can win the election. Let AA be the event that party As candidate wins, and let BB be the event that party Bs candidate wins. Does the outcome of one event determine the outcome of the other event? Are AA and BB mutually exclusive events? b. Discuss the conditions under which P(A and B) = P(A) x P(B) is true. Under what conditions is this not true? c. Discuss the conditions under which P(A or B) = P(A) + P(B) is true. Under what conditions is this not true? 3. Although we learn a good deal about probability in this course, the main emphasis is on statistics. Write a few paragraphs in which you talk about the distinction between probability and statistics. In what types of problems would probability be the main tool? In what types of problems would statistics be the main tool? Give some examples of both types of problems. What kinds of outcomes or conclusions do we expect from each type of problem? General Instructions As doctoral students, your assignments are expected to follow the principles of high-quality scientific standards and promote knowledge and understanding in the field of criminal justice. You should apply a rigorous and critical assessment of a body of theory and empirical research, articulating what is known about the phenomenon and ways to advance research about the topic under review. Research syntheses should identify significant variables, a systematic and reproducible search strategy, and a clear framework for studies included in the larger analysis. Assignments may be written in first person (I). All assignments should be clearly and concisely written, with technical material set off. Please do not use jargon, slang, idioms, colloquialisms, or bureaucratese. Use acronyms sparingly and spell them out the first time you use them. Please do not construct acronyms from phrases you repeat frequently in the text. Structure of Assignment Paper For purposes of this assignment, there is no layout structure required as far as the setup of this paper, with one exception. I would appreciate it if you used separate headers for question 1 and question 2. Sub-headers are also allowed but not required. Questions should strive to be no less than 250 words each with no maximum limit. I expect all papers to be in the latest APA edition, properly cited, and additional resources used besides classroom textbooks. Note: Your assignment will be checked for originality via the Turnitin plagiarism tool.

Statistics Homework Seven (15 pt) t-test: two independent samples Note: This assignment can be done quickly if utilizing SPSS From page 138, you will read, The Student’s t ratio is used for analyses that compare two groups that are independent. In a two-sample analysis, we are drawing two samples, finding the differences between the means of each group, and obtaining a distribution of these differences. This week you will determine if there is a statistically significant difference in mean Composite ACT Second Attempt Scores between students taking ACT prep and students not taking the ACT prep. This requires calculating a t static. The independent t-test requires the researcher to check for three assumptions. These assumptions are identified on page 139 if the text. This will require you to review the variance, skew, and kurtosis calculated in HW Assignment Two. o Are the ACT Second Attempt Score variances significantly different? Explain why or why not. (3 pt). o Are the data for each group normally distributed? Explain why or why not. (3 pt) o Using the independent t-test, determine if there is a statistically significant difference in second attempt ACT scores between students who took the ACT prep and those that did not take the prep. This will require calculation of t and comparing the calculation to the t critical value table on page 184. Is there a statistically significant difference? Why is there a difference? Explain how you came to that conclusion. (9 pt) In research, we often look at samples which have been matched on some criteria or pre- post-designs in which we are looking at a single group before and after some intervention (pg. 142). A repeated measure t-test is also labelled as a dependent t-test and a matched pairs t-test. The repeated t-test is called repeated because the same measure, or variable, is recorded from a sample twice. Generally, such as in our RSH data set, the first measure occurs at time one and the second measure occurs at time two. For our data set, RSH data set, ACT first attempt score was taken at time one, and ACT second attempt score was taken at time two. The repeated measure, or variable, for our data set is Composite ACT Score. A description of the matched pairs t-test is provided in Chapter 14, page 142. For this assignment, you will determine if there is a statistically significant difference in mean Composite ACT score for students who took the ACT prep course and for students who did not take the ACT prep course. The degrees of freedom for a matched pairs t test is the number of matched pairs minus one. Using the critical values table on page 184, determine if the calculated t-statistics are greater than the critical value for a two-tailed test at an alpha level of 0.05 (95% confidence that there is a difference from pre to post ACT scores). Provide the following: Null Hypotheses (one for the group of students that did not take the ACT, a second null hypothesis for the group of students who did take the ACT prep) (2 pt). Degrees of freedom for both t-tests. (2 pt) CV for both t-tests. (2 pt). t- value for both t-tests. (10 pt) A conclusion for accepting or rejecting each null hypothesis with an explanation for why each hypothesis was accepted or rejected. (4 pt)

Download sav FILE Requirements Download and use the following to complete: Lab Assignment #1 lab_assignment_01.docx Data file: wk02_leadership2026.sav Lab Assignment #1 Key

In this assignment, you will calculate confidence intervals for the quantitative variables in the Heart Rate Data Set. Steps Open the Heart Rate Excel Data Set and identify the quantitative variables. Make sure the data is sorted by category (e.g.male-at-rest, female-at-rest, etc.). Use the Data Analysis tools of Excel to construct 95% and 99% confidence intervals for all 8 categories of the sorted quantitative variables. Excel will calculate the margin of error given as the confidence interval in the output. Use this margin of error to create your 8 confidence intervals by both adding and subtracting it from the sample mean (calculated in unit 3). This creates a range of values that is the confidence interval. Create a Word document, and use your calculated results to explain what the confidence intervals tell us. What do these confidence intervals tell us about our heart rate data? How would you interpret the 95% and 99% intervals for resting heart rate? Compare the 99% and 95% intervals and explain why one is larger than the other even though we use the same sample mean value. Additional Instructions: Your assignment should be typed into a Word or other word-processing document, formatted in APA style. The assignments must include Running head A title page with Assignment name Your name Professors name Course Estimated time to complete: 3 hours

Assignment Instructions: Part 1: Research and Resource Collection (Library Exploration) Library Visit and Resource Identification: Visit your university or local library (physically or through online databases). Identify at least three credible sources (textbooks, academic articles, industry guides, etc.) that cover: The principles of survey design. Best practices for writing survey questions (e.g., avoiding bias, using clear language). Techniques for selecting a sample and ensuring survey validity and reliability. Case studies or examples of successful survey designs. Resource Summary: For each of the three selected resources, provide a summary (150-200 words) that includes: The main topics discussed in the resource. The relevance of the resource to understanding survey design. How the resource contributes to your knowledge of creating effective surveys. Part 2: Key Components of Survey Design Survey Design Principles: Write an analysis (400-500 words) addressing the following aspects of survey design: The importance of clear objectives: Why is it essential to define the purpose of the survey before designing it? Question types and structure: Discuss the different types of survey questions (e.g., open-ended, Likert scale, multiple choice) and when to use them. Avoiding bias: Explain common pitfalls that lead to biased questions and how they can be avoided. Layout and formatting: Discuss how the design and organization of a survey impact response rates and data accuracy. Sampling Techniques: Explain the different sampling techniques (e.g., random sampling, stratified sampling, convenience sampling) in the context of surveys. Discuss: How to select an appropriate sampling method based on the surveys goals. The importance of sample size in achieving reliable results. Part 3: Practical Application – Designing Your Own Survey Survey Design Project: Design a short survey (5-6 questions) on a topic of your choice (e.g., student satisfaction, consumer preferences, social behavior). Consider the following: Clearly state the surveys objective. Identify the target population and describe the sampling method you would use. Design questions that are clear, unbiased, and appropriate for the topic. Ensure a logical flow and effective formatting for the survey. Survey Rationale: Write a 300-400 word rationale explaining: Why you chose the topic and objectives for your survey. The reasoning behind your choice of question types and sampling method. How you ensured that your survey design minimizes bias and encourages accurate responses. Part 4: Reflection and Conclusion Critical Reflection: Reflect on the challenges and considerations involved in survey design. In 200-300 words, discuss: What you learned about creating effective surveys. The potential challenges you might face when conducting a survey in practice. How this assignment has influenced your understanding of data collection and research methods. Depth of Research (20%): Quality and relevance of the sources identified. Understanding of Survey Principles (20%): Clarity and depth of analysis in discussing survey design components. Practical Application (30%): Creativity and appropriateness in designing a survey and explaining the rationale. Reflection (30%): Insightful and thoughtful reflection on survey design challenges and lessons learned. This assignment encourages students to engage deeply with the principles of survey design, balance theory with practice, and apply what they learn in designing an effective survey. The structure of the assignment helps students develop critical skills in research, analysis, and practical application.