3. A study was conducted to determine if a doing homework while listeig to music increased retention of the material. A teacher asked 60 of their students if they complete thcr homework while listening to music. Thirty of the students said yes and thirty of the students said d. After collecting the data, it was determined that the students that completed the homework while listening to music, on average, had lower overall test grades than students that did not complete homewor on a nightly basis. Docs this study show that completing homework while not listening to music belps increase test scores? a. No, the difference could just be from sample variability. More students nced to be examined. b. No, because this was an obscrvational study the results might be ponfounded with overall study habits. Students that complete the homework without listening to music may be different than students that listen to music in some other way that affects overall test grades. c. Yes, becausc this is an observational study and the students that complete their homework while listening to music had lower test scores on average. d. Yes, because the study describe is a well-designod experiment with a treatment group. students that do homework while listening to music, and a control group, students that do not.

A study was conducted to determine whether big-city and small-town dwellers differed in their helpfulness to strangers. In this study, the investigators rang the doorbells of strangers living in a large City or small towns in the vicinity. They explained they had misplaced the address of a friend living in the neighbourhood and asked to use the phone. The following data show the number of individuals who admitted or did not admit the strangers (the investigators) into their homes: Helpfulness to strangers   Admitted strangers into their home  Didnot admit strangers into their home  Big city dwellers 60 90 Small town dwellers 70 30 State the dependent and independent variable  Is this a directional or non directional

A college student is interested in whether presoaking time has an effect on cleanliness of clothing.  He collects the dirty clothes from all of the people in his dorm and randomly assigns clothing to one of four presoak time conditions: 5 minutes, 10 minutes, 15 minutes, 20 minutes.  He then asks members of another dorm to rate the cleanliness of the items (they don’t know which clothing got which soaking time).  The data are presented below. C) Perform an LSD test and answer the questions that follow (SHOW ALL WORK!!! This can be on the same page as your other ANOVA hand work. Make sure it is inserted and/or uploaded): df error =   tcrit (df error)   MS error =   s =     LSD = _____________   Mean Comparisons:   Mean5 min vs. Mean10 min = |      ___            __       | = ___ ___              Greater than (>) LSD value? __   ___  Significant?__                   ­___   Mean10 min vs. Mean15 min = |__________________| =   ______             Greater…

A clinical psychologist is interested in comparing the effectiveness of short term relaxation and cognitive-behavioral therapy in treating mild depression.  An experiment is conducted in which 15 patients with mild depression are randomly selected and assigned 5 each to a relaxation therapy group, a cognitive/behavioral therapy group, and an attention placebo group.  Therapy is administered until the patient is judged no longer depressed or until 10 treatment sessions have elapsed.  The following data is obtained.  Scores are the number of sessions for each patient. Using an alpha of .05, test the hypothesis that there is a difference in effectiveness among these therapies.     Cognitive/Behavioral  Therapy Relaxation Therapy Attention-PlaceboGroup 56647 68797   5  8  9  7  6       What is the appropriate test?

A study of the effects of smoking on sleep patterns is conducted. The measure observed is the time, in minutes, that it takes to fall asleep. These data are obtained: Smokers: 63.3 56.0 22.1 47.6 53.2 48.1 52.7 34.4 60.2 43.8 23.2 13.8 Nonsmokers: 28.6 25.1 26.4 34.9 29.8 28.4 38.5 30.2 30.6 31.8 41.6 21.1 36.0 37.9 13.9 (a) Use R and report the number of observations for each group. (b) Use R and report the sample mean for each group. (c) Use R and report the sample standard deviation for each group. (d) Comment on what kind of impact smoking appears to have on the time required to fall asleep.

Do larger universities tend to have more property crime? University crime statistics are affected by a variety of factors. The surrounding community, accessibility given to outside visitors, and many other factors influence crime rate. Let x be a variable that represents student enrollment (in thousands) on a university campus, and let y be a variable that represents the number of burglaries in a year on the university campus. A random sample of n = 8 universities in California gave the following information about enrollments and annual burglary incidents.x  12.3 28.6  24.5 14.3  7.5   27.7 16.2 20.1y   23   72     39      23    15    30    15    25   a) Compute r. (Round your answer to four decimal places.)

Do larger universities tend to have more property crime? University crime statistics are affected by a variety of factors. The surrounding community, accessibility given to outside visitors, and many other factors influence crime rate. Let x be a variable that represents student enrollment (in thousands) on a university campus, and let y be a variable that represents the number of burglaries in a year on the university campus. A random sample of n = 8 universities in California gave the following information about enrollments and annual burglary incidents. x 10.9 30.4 24.5 14.3 7.5 27.7 16.2 20.1 y 23 76 39 23 15 30 15 25   (a) Make a scatter diagram of the data. Then visualize the line you think best fits the data. A scatter diagram has a horizontal axis labeled "x (student enrollment (in thousands))" with values from 7.5 to 30.4 and a vertical axis labeled "y (annual number of burglaries)" with values from 15 to 76. The scatter diagram has 8 points. A pattern goes up and…

A clinical psychologist is interested in comparing the effectiveness of short term relaxation and cognitive-behavioral therapy in treating mild depression. An experiment is conducted in which 15 patients with mild depression are randomly selected and assigned 5 each to a relaxation therapy group, a cognitive/behavioral therapy group, and an attention placebo group. Therapy is administered until the patient is judged no longer depressed or until 10 treatment sessions have elapsed. The following data is obtained. Scores are the number of sessions for each patient. Cognitive/BehavioralTherapyRelaxationTherapyAttention-PlaceboGroup568476810978109109 MS between = _________.