A major company would like to assess the impact of using a professional trainer to conduct a confidence-building workshop with its salespeople. A sample of 16 workers is obtained. Half (n = 8) attend the workshop and the other half (n = 8) serves as a control group. Two weeks later, each of the participants is given a questionnaire measuring the level of self-confidence. The data are as follows: Controls: M=17.5 SS=100 n=8 WorkShop M=22.7 SS=124 n=8 a. conduct the four steps of hypothesis testing to evaluate the significance of the treatment effect and calculate Cohen’s d to measure the size of the treatment effect. Use a two-tailed test with alpha level = .05

They then decided to determine whether the effect of the phone depended on how dependent people were on their phones. They had participants complete a scale to measure phone dependence (e.g., I would have trouble getting through a normal day without my phone) and classified them as high or low in dependence. They then analysed working memory task performance in a 2 (location: outside, desk) x 2(dependence: high, low) ANOVA. In this design, "dependence" is a(n) O a. Independent variable O b. Extraneous variable O c. Dependent variable O d. Subject variable

The director of student services at Oxnard College is interested in whether women are less likely to attend orlentation than men before they begin their coursework. A random sample of freshmen at Oxnard College were asked what their gender is and whether they attended orientation. The results of the survey are shown below: Data for Gender vs. Orlentation Attendance Women Men Yes 426 491 No 190 189 What can be concluded at the a = 0.10 level of significance? For this study, we should use Select an answer a. The null and alternative hypotheses would be: Ho: Select an answery Select an answerv Select an answerv (please enter a decimal and note that p1 and ul represent the proportion and mean for women and p2 and u2 represent the proportion and mean for men.) H: Select an answerv Select an answerv Select an answerv (Please enter a decimal) b. The test statistic ?v = (please show your answer to 3 decímal places.) c. The p-value = (Please show your answer to 4 decimal places.) d. The p-value…

Recent research indicates that the effectiveness of antidepressant medication is directly related to the severity of the depression (Khan, Brodhead, Kolts & Brown, 2005). Based on pretreatment depression scores, patients were divided into four groups based on their level of depression. After receiving the antidepressant medication, depression scores were measured again and the amount of improvement was recorded for each patient. The following data are similar to the results of the study. Low Moderate High Moderate Moderately Severe Severe 1.6 2.9 3.8 3.4 0.9 1.3 3 2.8 1.8 3.1 3.3 3.2 2.7 3.7 2.4 4.9 3.8 2.9 3.7 3.2 4.9 1.7 From this table, conduct an one-way ANOVA. Calculate the F-ratio and p-value. Be sure to round your answers to three decimal places. Assume all population and ANOVA requirements are met. F-ratio: p-value: What is your final conclusion? Use a significance level of a = 0.01. O There is sufficient evidence that there exists a significant difference between treatments. O…

You are a manager for Company ABC and decide to compile data and analyze your employees’ level of satisifaction. You create a survey to ask each employee to rate their level of satisfaction working at Company ABC. Table 1 shows data of 15 people employees that responded to your survey. Each of the employees have the same job title: Sales Representative. The data set includes variables regarding an employee ID, gender, ethnicity, region, pay rate, employee satisfaction rating. Each employee was asked to rate their level of satisfaction working at Company ABC. A composite score from 0 (lowest) to 5 (highest) is shown as the data variable employee satisfaction. Table 1: Employee Data on 15 Sales Representatives at Company ABC

In a clinical trial of 2022 subjects treated with a certain drug, 21 reported headaches. In a control group of 1745 subjects given a placebo, 24 reported headaches. Denoting the proportion of headaches in the treatment group by p, and denoting the proportion of headaches in the control (placebo) group by pe, the relative risk is p/pe. The relative risk is a measure of the strength of the effect of the drug treatment. Another such measure is the odds ratio, which is the ratio of the odds in favor of a headache for the treatment group to the odds in favor of a headache for the control (placebo) group, found by evaluating Pt/(1-Pt) The relative risk and odds ratios are commonly used in medicine and epidemiological studies. Find the relative risk and odds ratio for the Pc/(1-Pc) headache data. What do the results suggest about the risk of a headache from the drug treatment? Find the relative risk for the headache data. The relative risk = (Round to three decimal places as needed.)

Many people take ginkgo supplements advertised to improve memory. Are these over-the- counter supplements effective? In a study, elderly adults were assigned to the treatment group or control group. The 104 participants who were assigned to the treatment group took 40 mg o ginkgo 3 times a day for 6 weeks. The 115 participants assigned to the control group took a placebo pill 3 times a day for 6 weeks. At the end of 6 weeks, the Wechsler Memory Scale was administered. Higher scores indicate better memory function. Summary values are given in the following table: N Ginkgo 104 5.7 0.6 Placebo 115 5.5 0.5 Perform the appropriate test to determine if taking 40mg of ginkgo 3 times a day is effective in increasing mean performance on the Wechsler Memory Scale. > Is the study observational or designed experiment? > Can you conclude association or causation with this type of study? Is this a matched-pair dependent test or two-sample independent test?