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 2.4 0.2 2.5 3.5 1.6 1.7 2.7 4.3 2.7 3.4 2 3.4 0.5 1.2 5.2 5.1 2.4 2.3 4 3.5 1.8 0.3 4.1 3.8 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 α=0.05. (Select one):  There is sufficient evidence that there exists a significant difference between treatments. There is not enough evidence to determine a difference between the treatments.

A researcher is interested in learning more about the protective effects of exercise.  He conducts a study where he collects information about stress levels (measured on a multi-item Likert scale) and hours of exercise completed in a week (1,2,3,4,etc.,etc.).  What type of statistical test should be used?

6.50 How's it going?: The American National Election Studies (ANES) collects data on voter attitudes and intentions as well as demographic information. In this question we will focus on two variables from the ANES dataset (ANES, 2012). region (levels: Northeast, North Central, South, and West) whether the respondent feels things in this country are generally going in the right direction or things have pretty seriously gotten off on the wrong track To keep calculations simple we will work with a random sample of 500 respondents from the ANES dataset. The distribution of responses are as folows: Right Direction Wrong Track Total Northeast 29 54 83 North Central 44 77 121 South 62 131 193 West 36 67 103 Total 171 329 500 There are TWO parts to this question. One is a Chi-Squared GOF and one is a Chi-Squared Test for Independence. Think about the differences between the two tests to determine which one to use on which part. a) Region: According to the 2010 Census, 18% of US residents live…

A recent study investigated whether the number of positive health behaviors (e.g., exercising, eating healthy) is predictive of a person's score on a happiness index, such that as positive health behaviors go up, happiness goes up. The results from the study, which was conducted with 12 people, were as follows: r = 0.63 and SSY = 56.0. What is the MSregression? What is the MSresidual? What is the calculated test statistic? Given the value of your calculated test statistic and your critical test statistic, do you reject the null?

The DASS-21 questionnaire is a validated measure of depression, anxiety, and stress. For the general population, the mean for anxiety is µ = 4.2. Anxiety levels are calculated based on self-reported answers to questions on a scale from 0 through 42, with lower scores indicating lower anxiety.   Participants with gastrointestinal issues (specifically inflammatory bowel disease, IBD) completed the DASS-21. Use the data presented below to determine whether having gastrointestinal issues like IBD significantly increases risk for anxiety. Test whether or not the performance of this sample is significantly higher than the normal population using the proper t-test.  Here are the data:   Anxiety scores: 12, 15, 10, 8, 10, 5, 10, 13, 4, 6   ANALYSES AND UNGRADED OPTIONAL GUIDING QUESTIONS: 1a. Identify the Indep.Variable:__                  Dep.Variable:__ Is it the Hypothesis one-tailed or two-tailed?__ Proper t-test statistic:__ Why? _ State Hypotheses mathematically: H0:__ H1:__  State…

Please answer (b) and (d)

A headache medicine is tested on an experimental group of 50 patients who have headaches. Out of these people, 37 of them say they felt better when taking the medicine. A fake pill (placebo) is given to 50 different patients, of whom 27 say they felt better after taking the "medicine". Is this enough evidence to show that a higher percentage of people in the experimental group were cured, compared to the control group? (Use a = .01) Type of Test: Hypotheses: Test Statistic: P-value: Decision: XC. In a sentence, what can be said about the medicine?

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. F-ratio: Low Moderate p-value: 2.2 3.1 0.6 2.6 0.5 0 High Moderate 1.5 2.1 3.3 2.3 2.1 4.6 Moderately Severe 2.7 4.7 4.7 4.6 3.7 3.3 From this table, conduct ANOVA. Calculate the F-ratio and p-value. Be sure to round your answers to three decimal places. Severe 3.8 2.4 5.3 4.7 4.2 4 What is your final conclusion? Use a significance level of a = 0.02. O There is sufficient evidence that there exists a significant difference between treatments. O There is not enough evidence to determine a difference…

The time married men with children spend on child care averages 6.8 hours per week. You belong to a professional group on family practices that would like to do its own study to determine whether the time married men in your area spend on child care per week differs from the reported mean of 6.8 hours per week. A sample of 40 married couples will be used with the data collected showing the hours per week the husband spends on child care. The sample data are contained in the table below. 10.0 8.5 8.3 0.4 3.6 10.6 6.6 9.3 5.7 7.9 10.4 9.5 10.0 7.9 11.0 2.4 8.1 5.4 4.5 7.6 3.7 6.1 6.1 0.4 7.3 8.0 7.7 6.3 4.7 8.9 8.3 9.0 7.3 7.3 8.0 11.9 9.0 8.7 5.7 9.5 a. What are the hypotheses if your group would like to determine whether the population mean number of hours married men are spending in child care differs from the mean reported by Time in your area? Select your answer 6.8 H.:uSelect your answer 6.8 b. What is the sample mean (to 2 decimals)? Calculate the value of the test statistic (to 2…

Part II. Complete the ANOVA table below using the study description. Answer the questions to determine if there is in fact a significant difference between the three groups. A psychologist would like to examine the effects of sugar consumption on the activity level of preschool children.  Three samples of children are selected with n = 5 in each sample.  One group gets no sugar, one group gets a small dose, and the third group gets a large dose.  The psychologist records the activity level for each child.  The data from this experiment are presented below.  1. Do these data indicate any significant differences among the three groups?  Test with α = .05.