Inference for Relationships Checkpoint Question 1 Select one answer. 10 points A psychologist wants to study whether there is a difference in the effectiveness of two different talk therapy techniques (exposure therapy or cognitive behavioral therapy) on phobia symptom severity. The psychologist randomly assigns a large group of clients suffering from a phobia into one of the two treatment conditions: exposure therapy or cognitive behavioral therapy. After 8 weeks of therapy, the psychologist assesses the phobia symptoms of both groups of clients using a questionnaire that gives a number between 0 to 40 to indicate the severity of the client's phobia symptoms. Which of the following is the most appropriate statistical test to use to determine if there is a significant difference between exposure therapy and cognitive behavior therapy on phobia symptoms? 1. Inference for regression 2. Chi-squared test for independence 3. ANOVA 4. Two-sample t-test 5. Matched pairs t-test Question 2 Select one answer. 10 points A chemistry professor suspects that there is a relationship between the number of classes a student misses and that student's score on the final exam (from 0 to 100%). The professor chooses a random sample of students in Introduction to Chemistry and collects data about each student's final exam score and number of missed days of class. Which of the following is the most appropriate statistical test to use to determine if there is a relationship between number of missed classes and final exam scores? 1. ANOVA 2. Two-sample t-test 3. Chi-squared test for independence 4. Matched pairs 5. Inference for regression Question 3 Select one answer. 10 points Suppose a classroom teacher wants to measure whether offering candy as a reward will increase the number of times that a student raises his/her hand to answer a question in class. A study yields the following data. Ro w C1 C2 1 9 12 2 7 8 3 15 14 Ro w C1 C2 4 10 11 5 8 7 If column 1 is the number of candy rewards given for answering questions during a lesson, and column 2 is the number of students who raise their hand to answer questions during a lesson, which of the following is the appropriate inference method to analyze these data? 1. Inference for regression 2. Matched pairs 3. Two independent samples Question 4 Select one answer. 10 points We want to explore the relationship between the prices of diamond rings and the weights of their diamond stones. Which of the following is the most appropriate statistical test to use to determine if there is a relationship between the price and weight of diamond rings? 1. Inference for regression 2. ANOVA 3. Chi-squared test for independence 4. Two-sample t-test 5. Matched pairs t-test Question 5 Select one answer. 10 points A researcher wants to explore the relationship between two variables: Time 1 and Time 2. Time 1 Time 2 421 400 390 383 459 436 384 362 403 392 A group of student athletes was training for an obstacle course event by practicing a variety of exercises. Their coach wanted to know if the exercises were in fact related to their time to complete the obstacle course. Time 1 was each athlete's time (in seconds) for 20 repetitions of shuttle runs (running back and forth between 2 cones placed 25 meters apart) during training. Time 2 was the same athlete's time (in seconds) to complete the obstacle course during the competition. If the coach wants to see if there was an association between time to complete 20 shuttle runs during training (in seconds) and the time to complete the obstacle course during competition (in seconds), which of the following is the appropriate inference method to analyze these data? 1. Inference for regression 2. Two independent samples 3. Matched pairs Question 6 Select one answer. 10 points Movie executives want to know if a movie watcher's heart rate increases when they watch certain types of movies. Subjects in the experiment were given a free movie ticket and randomly assigned to watch one of four movies: an action-adventure film, a horror film, a romantic comedy, or an animated children's film. They measured the average heart rate of all subjects while watching the assigned film. Which of the following is the most appropriate statistical test to use to test if the average heart rate of the movie watchers was different for the four types of movies? 1. ANOVA 2. Matched pairs t-test 3. Two-sample t-test 4. Chi-squared test for independence 5. Inference for regression Question 7 Select one answer. 10 points To test whether Internet use increases depression score, we measure the depression scores of a random sample of non-Internet- users, have them use the Internet for a specified time, then measure their depression scores again. Which of the following is the most appropriate statistical test to use to test if Internet use decreases depression score? 1. ANOVA 2. Inference for regression 3. Two-sample t-test 4. Matched pairs t-test 5. Chi-squared test for independence Question 8 Select one answer. 10 points A physical therapy researcher was interested in determining the impact of two different exercises. The investigator suspected that the two exercises produced a different level of activity in the muscle. Each of 16 subjects performed both exercise 1 and exercise 2, and the results are shown (for each subject, the order of the exercises was randomly assigned and sufficient rest time was provided between the two exercises). Which of the following is the most appropriate statistical test to use to determine the impact of the two difference exercises? 1. Matched pairs t-test 2. Inference for regression 3. Two-sample t-test 4. ANOVA 5. Chi-squared test for independence Question 9 Select one answer. 10 points A researcher wants to explore the relationship between the following two variables, Weight 1 and Weight 2. Suppose that Weight 1 is the weight (in pounds) of a sample of five individuals before beginning a weight-loss diet, and Weight 2 is the weight in (pounds) of the same five individuals after the diet. If we would like to test the effectiveness of the diet, which of the following is the appropriate inference method to analyze these data? 1. Inference for regression 2. Matched pairs 3. Two independent samples Question 10 Select one answer. 10 points Suppose an economist wishes to determine the relationship between the age and price of houses. A study yields the following data: If column 1 is the price (in hundreds of thousands of dollars) of a sample of five houses from ten years ago, and column 2 is the price (in hundreds of thousands of dollars) of the same homes today, which of the following is the appropriate inference method to analyze these data? 1. Inference for regression 2. Matched pairs 3. Two independent samples Question 11 Select one answer. 10 points We want to test for a relationship between race/ethnicity and marital status (married/never married/divorced/widowed). Which of the following is the most appropriate statistical test to use to determine if there is a relationship between race and marital status? 1. ANOVA 2. Matched pairs t-test 3. Inference for regression 4. Chi-squared test for independence 5. Two-sample t-test Question 12 Select one answer. 10 points A researcher wants to explore the relationship between two variables: Time 1 and Time 2. Time 1 Time 2 421 400 390 383 459 436 384 362 403 392 If Time 1 is the time (in seconds) that it took for a random sample of five female college tennis players to run a mile, and Time 2 is the time (in seconds) of a random sample of five female college basketball players to run a mile, which of the following is the appropriate inference method to analyze these data? 1. Matched pairs 2. Inference for regression 3. Two independent samples