Antidepressants A study compared the effectiveness of several antidepressants by examining the experiments in which they had passed the FDA requirements. Each of those experiments compared the active drug with a placebo, an inert pill given to some of the subjects. In each experiment some patients treated with the placebo had improved, a phenomenon called the placebo effect. Patients’ depression levels were evaluated on the Hamilton Depression Rating Scale, where larger numbers indicate greater improvement. (The Hamilton scale is a widely accepted standard that was used in each of the independently run studies.) The following
- a) Is it appropriate to calculate the
correlation ? Explain. - b) The correlation is 0.898. Explain what we have learned about the results of these experiments.
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- Urban Travel Times Population of cities and driving times are related, as shown in the accompanying table, which shows the 1960 population N, in thousands, for several cities, together with the average time T, in minutes, sent by residents driving to work. City Population N Driving time T Los Angeles 6489 16.8 Pittsburgh 1804 12.6 Washington 1808 14.3 Hutchinson 38 6.1 Nashville 347 10.8 Tallahassee 48 7.3 An analysis of these data, along with data from 17 other cities in the United States and Canada, led to a power model of average driving time as a function of population. a Construct a power model of driving time in minutes as a function of population measured in thousands b Is average driving time in Pittsburgh more or less than would be expected from its population? c If you wish to move to a smaller city to reduce your average driving time to work by 25, how much smaller should the city be?arrow_forwardChoose one of the following procedures for each of the research scenarios described. Rose intends to explore the hypothesis that there are only three or four underlying factors that may be used to reproduce the correlation between responses to her questionnaire on learners' interests.arrow_forwardRecent 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 High Moderate Moderate Moderately Severe Severe 0 2.6 2.7 2.7 1.7 2.5 3.2 3.3 2.2 3 3.2 5.2 0.6 1.8 3.8 1.5 1.9 1.9 3.8 5.9 1.3 1.2 2.4 2.9 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 απ 0.02. There is not enough evidence to determine a difference between the treatments. There is…arrow_forward
- 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 High Moderate Moderately Moderate Severe Severe 3.1 1.3 5.1 3.5 2.3 3.3 3.6 2.9 2.7 2.9 1.8 4.2 3 4 4.2 2 3.9 3.9 4.7 2.1 0.5 2.5 2.2 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 = 0.02. O There is not enough evidence to determine a difference between the treatments. O There is…arrow_forwardA manufacturer of pens has hired an advertising agency to develop an advertising campaign for the upcoming holiday season. To prepare for this project, the research director decides to initiate a study of the effect of advertising on product perception. An experiment is designed to compare three different advertisements. Advertisement A greatly undersells the pen's characteristics. Advertisement B slightly undersells the pen's characteristics. Advertisement C slightly oversells the pen's characteristics. A sample of 18 adult respondents, taken from a larger focus group, is randomly assigned to the three advertisements (so that there are 6 respondents to each advertisement). After reading the advertisement and developing a sense of "product expectation," all respondents unknowingly receive the same pen to evaluate. The respondents are permitted to test the pen and the plausibility of the advertising copy. The respondents are then asked to rate the pen from 1 to 7 (lowest to highest) on…arrow_forwardResearchers investigated factors that influenced how much people like each other based on first meeting. They were particularly interested in the effects of eye-to-eye contact and smiling. They collected data from 20 participants. Each participant was asked to wait in a small room while the experimenter went next door, ostensibly to gather the materials needed for the study. While the participant was waiting, a confederate of the experimenter entered the room and sat in a chair facing the participant, and asked "Are you waiting for the experiment?". Immediately after asking the question, the confederate smiled at, and/or looked directly into the eyes of, the participant. This was done in four conditions: for five participants the confederate smiled and looked into the participant's eye, for five participants the confederate smiled but did not look into the participant's eye, for five participants the confederate did not smile but did look into the participant's eyes, and for five…arrow_forward
- 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. LowModerate HighModerate ModeratelySevere Severe 0.5 2.7 3.4 2.6 1.7 0.8 2.6 5.3 3.3 1.9 1.1 4 2.6 1.4 4.3 2.6 1.4 2.9 3.6 4.6 3.1 3.2 4.8 1.4 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:arrow_forwardRecent 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. LowModerate HighModerate ModeratelySevere 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…arrow_forwardRecent 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. LowModerate HighModerate ModeratelySevere Severe 0.3 1.2 2.2 1.8 3.8 1.7 1.4 2.8 3.2 0.4 0.6 2.6 2.3 1.2 1.6 2.6 2 3.2 1.6 2.2 0.6 1.2 1.6 1 2.7 1 2.2 0.6 1.4 1.6 3.3 2.7 2.2 2.9 3.7 2.6 0.9 0.7 3.4 3.1 2.6 1.7 0.8 1.8 2 1.4 1.6 4.1 1.7 0.9 3.3 2.3 1.6 1.1 3.5 1.4 3.5 1.9 0.4 4.2 1.5 2.3 2.2 2.9 1.4 2.2 2.7 2.8 2.1 1.9 1.9 3.9 1.5 2.7 0.8 1.5 1 3 2.1 3.7 1.5 0.9 2.4 1.9 2.7 3.2 0.8 2.7 2.2 2.9 1.8 1.2 2.4 1.7 3.2 1.3 2.2 2.4 1.1 1 2.6 2…arrow_forward
- 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. LowModerate HighModerate ModeratelySevere Severe 2.2 1.4 3.4 3.4 1.5 1.4 3.5 2.8 2.8 3.1 2.7 2.3 1.7 2.6 4.4 3.6 1.3 1.5 2.6 3.2 1.3 2.6 2.8 3.5 Fill in the summary table for the ANOVA test: degrees of freedom (d.f.) Sum of Squares (S.S.) Mean Square (M.S.) Between Within Total From this table, obtain the necessary statistics for the ANOVA:F-ratio (F-test statistic): p-value: η2η2 (Eta squared = Sum of squares betweenSum of squares totalSum…arrow_forwardPlease help. Thanks! Experiment 5: What is the relationship between soft drinks and obesity?The director of an obesity clinic in a large northwestern city believes that drinking soft drinks contributes to obesity in children. To determine whether a relationship exists between these two variables, she conducts the following pilot study. Eight 12-year-old male volunteers are randomly selected from children attending a local junior high school. Parents of the children are asked to monitor the number of soft drinks consumed by their child over a 1-week period. The children are weighed at the end of the week and their weights converted into body mass index (BMI) values. The BMI is a common index used to measure obesity and takes into account both height and weight. An individual is considered obese if they have a BMI value 30. The following data are collected: Please provide needs to have the following information: Hypotheses: both alternative and the null . Mean and standard deviation of…arrow_forwardAs an admissions counselor, I am interested in understanding whether or not there is a difference in stress levels not only between different majors but also between different classes (Freshman v. Seniors). I gather the following data from students from three majors (Psychology, Chemistry, and Engineering), that are in their freshmen or senior years and ask them about their stress levels (scale of 1-10, with lower numbers meaning less stress). Using the data below, test whether there are effects of class, major, or an interaction between them at an alpha of 0.05. Psychology Chemistry Engineering Freshmen 3, 4, 4, 2, 4 4, 5, 7, 8, 4 5, 7, 7, 8, 5 Senior 4, 5, 5, 3, 5 8, 5, 6, 7, 7 9, 9, 8, 7, 9 Complete the ANOVA summary table below: Source SS df MS (variance) F MAJOR CLASS MAJOR*CLASS ERROR/RESIDUAL Nothing here TOTAL Nothing here Nothing here What can we conclude?…arrow_forward
- Functions and Change: A Modeling Approach to Coll...AlgebraISBN:9781337111348Author:Bruce Crauder, Benny Evans, Alan NoellPublisher:Cengage LearningGlencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill