41. A researcher wants to test the hypothesis that right-handed people will have different visual acuity in their left and right eyes. What sort of test should the researcher use? Select one: a. one-tailed test with two dependent samples b. one-tailed test with two independent samples c. two-tailed test with two dependent samples d. two-tailed test with two independent samples 42. To test the effectiveness of a new therapy, a researcher compares the health outcomes of 45 patients who receive the therapy and 38 patients in a control condition. In a two-tailed test, the researcher obtains a t-statistic of 1.83. What is the strictest threshold at which this result could be considered significant? Select one: a. P<0.1 b. P<0.05 c. P<0.01 d. P<0.001 43. A researcher is conducting a study comparing the effects of drug treatments on hours of sleep across three groups. Group 1 is taking Drug A, Group 2 is taking Drug B, and Group 3 is a control group not taking any drug. What statistic would be most appropriate to compare the mean number of hours of sleep across the three groups? Select one: a. paired samples t test b. independent t test c. analysis of variance d. factor analysis 44. What does the denominator represent in the formula for an F-statistic used in an ANOVA?

Select one: a. effect size of the experimental treatment b. grand mean across all observations c. one minus the number of observations d. variation within treatment groups 45. What is one way that the F-statistic differs from the t-statistic Select one: a. It can never be negative. b. It has a continuous distribution. c. It depends on degrees of freedom. d. It has a symmetric distribution. 46. According to the ANOVA test, which statement is true if the variation of treatment means from the grand mean is much larger than the variation within treatment groups? Select one: a. The risk of Type II error is increased. b. The sample size may be too small. c. The treatment groups have different means. d. The samples have overlapping distributions. 47. Five players on a basketball team score a total of 85 points in a game. An analyst performs a chi-square test to find out whether the five players' point totals differ significantly from one another. According to the null hypothesis, how many points would each player be expected to score? Select one: a. 0 b. 9 c. 13 d. 17 48. The table shows the areas of study chosen by freshmen at a liberal arts college over the last 50 years. The admissions office compares the choices of this year's incoming freshmen to these rates using a chi-square test, with a significance threshold of p<0.01. What is the critical value of the test statistic? Select one: a. 7.8 b. 9.2 c. 13.3

d. 15.1

49. The table shows the areas of study chosen by freshmen at a liberal arts college over the last 50 years. This year's freshmen class has 500 students. If students' choices this year reflect the historical averages, how many freshmen would be expected to major in the social sciences? Select one: a. 115 b. 140 c. 165 d. 170 50. A researcher uses linear regression to analyze the association between people's ages in years and their score on a depression scale. Age is the independent variable in the model, and the number of points on the depression scale is the dependent variable. The mean age is 58, the mean depression score is 7, and the slope of the regression line is 0.2. Based on the regression model, what is the expected depression score of a 72-year-old? Select one: a. 7.2

b. 9.8 c. 11.3 d. 14.0 51. A researcher is studying the relationship between academic and sports performance in 100 college athletes. She runs a regression model with number of games started as the independent variable and grade point average as the dependent variable. This model yields a slope of b=- 0.3. A two-tailed test of this estimate produces a t-statistic of -2.1. Assuming a significance threshold of p<0.05, how should the researcher interpret the results? Select one: a. Each additional game played is associated with a 0.3 point decline in GPA. b. 30% of the variation in GPA can be explained by the number of games played. c. Grade point average and number of games played are positively associated. d. There is no reliable association between GPA and number of games played. 52. A sociologist wants to examine academic performance across grade levels in an elementary school. The number of students is not the same in each grade. Which sampling method would be most appropriate? Select one: a. simple random sampling b. systematic random sampling c. stratified random sampling d. cluster sampling 53. A researcher asks children to do a math test. Half of the children are told they will be rewarded for every correct answer; the others will receive no reward. The researcher will compare the mean test scores for the two groups. What type of research design is this? Select one: a. Census

b. Experiment c. Observational study d. Survey 54. Simple random sampling is used in various study designs to allow for Select one: a. greater variety in outcome values. b. targeted samples of specific subgroups. c. a sample that is representative of its population. d. greater statistical significance levels. 55. To increase the generalizability of a study's results, participants must be Select one: a. approximately the same age. b. blinded to the purpose of the research. c. observed multiple times. d. representative of the population of interest.

56. In research studies, which situation demonstrates self-selection bias? Select one: a. In an online survey on gun control, gun owners were twice as likely to respond as non- owners. b. For a statewide poll, a newspaper only contacted residents of urban areas. c. In an aging study, men were more likely than women to die before study completion. d. In an experiment, most of the female participants were assigned to the control group by chance.

57. A guidance counselor wants to administer a survey to students in her school. Why might she choose stratified sampling over simple random sampling? Select one: a. To reduce the chance of self-selection bias in the sample. b. To ensure that students from all grades are represented.

c. To account for the school's relatively small population size. d. To increase the total response rate for the survey. 58. What is the best way to decide which subjects should be placed in control and treatment groups in an experiment? Select one: a. order of enrollment b. pre-screening c. random assignment d. self-selection 59. Besides random selection, which study design increases the generalizability of survey results?

Select one: a. allowing open-ended responses b. increasing the sample size c. offering a monetary incentive d. using an in-person interview format 60. In a research study, what type of research design is most appropriate for establishing causality? Select one: a. between-subjects b. experimental c. observational d. survey