Researchers at the University of Houston decided to test the hypothesis that restaurant servers who squat to the level of their customers would receive a larger tip (“Effect of Server Posture on Restaurant Tipping,” Journal of Applied Social Psychology [1993]: 678–685). In the experiment, the waiter would flip a coin to determine whether he would stand or squat next to the table. The waiter would record the amount of the bill and of the tip and whether he stood or squatted.
a. Describe the treatments and the response variable.
b. Discuss possible extraneous variables and how they could be controlled.
c. Discuss whether blocking would be necessary.
d. Identify possible confounding variables.
e. Discuss the role of random assignment in this experiment.
Want to see the full answer?
Check out a sample textbook solutionChapter 2 Solutions
Introduction to Statistics and Data Analysis
- Research is interested in the relationship of video games of high school students' SAT scores, and he hypothesizes that students who play video games for a longer time tend to have a lower SAT score. To test his hypothesis, he randomly selected 60 high school students and asked: 1) how many hours do you spend playing video games each week? 2) what is your SAT score? a What is the research question? BWhat is/are the variable(s)? Are they categorical or continual variables? C What statistical test can be used to answer the research question?arrow_forwardDo people feel hungrier after sampling a healthy food? The authors of a consumer research paper carried out a study to answer this question. They randomly assigned volunteers into one of three groups. The people in the first group were asked to taste a snack that was described as a new health bar containing high levels of protein, vitamins, and fiber. The people in the second group were asked to taste the same snack but were told it was a tasty chocolate bar with a raspberry center. After tasting the snack, participants were asked to rate their hunger level on a scale from 1 (not at all hungry) to 7 (very hungry). The people in the third group were asked to rate their hunger but were not given a snack. The data in the table are consistent with summary quantities given in the paper (although the sample sizes in the actual study were larger). Treatment Group Healthy Tasty 5 8 7 Hunger Rating No Snack 3 4 4 4 1 4 2 7 3 6 2 5 6 5 5 4 7 5 2 3 4 6 4 4 Sample Mean 5.6667 3.4444 4.2222 Sample…arrow_forwardDo people feel hungrier after sampling a healthy food? The authors of a consumer research paper carried out a study to answer this question. They randomly assigned volunteers into one of three groups. The people in the first group were asked to taste a snack that was described as a new health bar containing high levels of protein, vitamins, and fiber. The people in the second group were asked to taste the same snack but were told it was a tasty chocolate bar with a raspberry center. After tasting the snack, participants were asked to rate their hunger level on a scale from 1 (not at all hungry) to 7 (very hungry). The people in the third group were asked to rate their hunger but were not given a snack. The data in the table are consistent with summary quantities given in the paper (although the sample sizes in the actual study were larger). TreatmentGroup Hunger Rating SampleMean SampleStandardDeviation Healthy 5 8 7 4 7 3 4 7 6 5.6667 1.7321 Tasty 4 1 5 2 6 2 5 3 4 3.5556…arrow_forward
- An American Automobile Association (AAA) study investigated the question of whether car owners or truck owners were more likely to change their own blown tire. The situation referred to in the study stated the following: “If you blew a tire on a trip, would you change the tire yourself?” A sample representative of the data used by AAA showed 663 of 818 car owners said that they would change the tire themselves while 541 of 733 truck owners said they would change the tire themselves. x n car owners 663 818 truck owner 541 733 The AAA research hypothesis was that truck owners would be more likely to change their tire themselves. Formulate the null and alternative hypotheses for this study. Let car owners be population What is the percentage of car owners who indicated that they would change their own tire?arrow_forward"Snoqualmie" is a name shared by a waterfall and a tribe of Native Americans. In a study of the cultural importance of the waterfall, two groups of the Snoqualmie tribe were randomly surveyed. One group consisted of Snoqualmie members living less than 25 miles from the waterfall. Another group consisted of Snoqualmie members living more than 25 miles from the waterfall. The researchers asked each member to rate the cultural importance of the waterfall as low, medium, or high. Data from the study are presented in the following table. Members Living More Than 25 Miles from the Waterfall Members Living Less Than 25 Miles from the Waterfall Total Low 25 17 42 Medium 8 21 29 High 12 17 Total 38 50 88 If the distributions of ratings are the same for those Snoqualmie members living less than 25 miles from the waterfall and those living more than 25 miles from the waterfall, which of the following is equal to the expected count of members living less than 25 miles from the waterfall who rated…arrow_forward“Snoqualmie” is a name shared by a waterfall and a tribe of Native Americans. In a study of the cultural importance of the waterfall, two groups of the Snoqualmie tribe were randomly surveyed. One group consisted of Snoqualmie members living less than 25 miles from the waterfall. Another group consisted of Snoqualmie members living more than 25 miles from the waterfall. The researchers asked each member to rate the cultural importance of the waterfall as low, medium, or high. Data from the study are presented in the following table. Members Living More Than 25 Miles from the Waterfall Members Living Less Than 25 Miles from the Waterfall Total Low 25 17 42 Medium 8 21 29 High 5 12 17 Total 38 50 88 If the distributions of ratings are the same for those Snoqualmie members living less than 25 miles from the waterfall and those living more than 25 miles from the waterfall, which of the following is equal to the expected count of members living less than 25 miles from the…arrow_forward
- only need help with the questions in the second picture attached.arrow_forwardA research study wanted to examine whether religious belief and gender are related in their state. They selected a representative sample of men and women in their State.Select the null and alternative hypothesis of the test: A. H0: there is no relationship between gender and belief about human origins Ha: there is a relationship between gender and belief about human origins B. H0: there is a relationship between gender and belief about human origins Ha: there is no relationship between gender and belief about human origins Results of the study are summarized in this table for the Belief about human origins: religious texts evolutionary theory total male 30 36 66 female 108 89 197 total 138 125 263 The degrees of freedom for the the ?2 statistic are Round the following numbers to two places after the decimal:The test statistic is ?2 = with a p-value = The conclusion of the test at the 5% significance level is Gender and belief about human origins are…arrow_forwardA seven-year medical research study reported that women whose mothers took the drug DES during pregnancy were twice as likely to develop tissue abnormalities that might lead to cancer as were women whose mothers did not take the drug. a. This study compared two What were the populations? b. Do you suppose the data were obtained in a survey or an experiment? c. For the population of women whose mothers took the drug DES during pregnancy, a sample of 3980 women showed that 63 developed tissue abnormalities that might lead to Provide a descriptive statistic that could be used to estimate the number of women out of 1000 in this population who have tissue abnormalities. d. For the population of women whose mothers did not take the drug DES during pregnancy, what is the estimate of the number of women out of 1000 who would be expected to have tissue abnormalities? e. Medical studies often use a relatively large sample (in this case.3980).Why?arrow_forward
- Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGALAlgebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:CengageBig Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillCollege Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning