A researcher wants to examine the effect of caffeine on participants’ ability to concentrate. How could the researcher address this question using a simple experiment? What are the pros and cons of this design choice? What is/are the appropriate analysis/analyses? How could the researcher address this question using a matched-pairs design? What are the pros and cons of this design choice? What is/are the appropriate analysis/analyses? How could the researcher address this question using a repeated measures design? What are the pros and cons of this design choice? What is/are the appropriate analysis/analyses?

Top management of a large multinational corporation wants to create a culture of innovativeness and change. A consultant hired to assess the company's organizational culture finds that only 15% of employees are open to new ideas and approaches toward their work. One of his recommendations for the company is to conduct seminars for employees in order to disseminate and reinforce the new corporate philosophy. This is done for a six month trial period after which its value in changing employee attitudes will be assessed. Write the null and alternative hypotheses. 2. Based on data collected after the trial period, the company constructed a 95% confidence interval for the proportion of all employees open to new ideas and approaches toward their work. The resulting interval is 18% to 22%. What conclusion should the company reach about the seminars?

Exercise 2: The school board of Two Guns, Texas is deeply concerned that their public school teachers are quitting their jobs and accepting teaching positions in other parts of the state. Some members of the school board think that the reason why teachers are quitting is because their weekly salaries are lower than those offered by other school boards in the state. The school board hires you to conduct a significance test. The research question: Do teachers in other parts of Texas earn higher average weekly salaries than those working in the Two Guns school district? There is no estimate of the population standard deviations. The significance level will be set at 5%. Step 1: Test Set-up Question 1: How large a sample is needed to achieve 80% statistical power? Based on past research Cohen's d effect size is estimated at 0.40, which is a small effect. See the table below: Cohen's d ES Thresholds Small 0.2 Medium 0.5 Large 0.8 Here are the results of an a priori power analysis run using…

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If gender is the independent variable of a quasi-experiment, this experiment must have a between-subject design. Group of answer choices True False

The Intention to Treat (ITT) analysis should be used in the following trial(s): Superiority trial  Non-inferiority trial  Equivalence trial  All of the above trials

Under what circumstances is it advisable to switch to a between-subjects design instead of using a within-subjects design?

A doctor wanted to study the effect of four different treatments on mental health. A group of 100 adults experiencing depression volunteered for the study. The doctor randomly assigned one-fourth of them to each of four groups. Group 1 followed a specific exercise plan, group 2 followed a specific diet plan, group 3 followed an exercise and diet plan, and group 4 did not follow any plan. After 4 weeks, the doctor contacted each participant and asked them if they felt any better. The results are displayed in the table.    The doctor would like to know if these data provide convincing evidence that the distribution of responses differs across the treatment groups in the population of all patients like these. The random condition is met. The 10% condition is not needed because random sampling did not take place. This table of expected counts shows that all expected counts are at least 5.   What is the value of the chi-square test statistic? χ‑2 = 5.03 χ‑2 = 6.26 χ‑2 = 25.33 χ‑2 = 39.22

The sales for Sunflowers Apparel, a chain of upscale clothing stores for women, have increased during the past 12 years as the chain has expanded the number of stores open. Until now, Sunflowers managers selected sites based on subjective factors, such as the availability of a good lease or the perception that a location seemed ideal for an apparel store. As the new director of planning, you need to develop a systematic approach that will lead to making better decisions during the site selection process. As a starting point, you believe that the size of the store significantly contributes to store sales, and you want to use this relationship in the decision-making process. To examine the relationship, a sample of 14 stores was selected. The results are recorded in the accompanying table:   Store Size (thousands of sq. ft) Annual Sales (millions of $) 1 1.7 3.7 2 1.6 3.9 3 2.8 6.7 4 5.6 9.5 5 1.3 3.4 6 2.2 5.6 7 1.3 3.7…