stats final exam
89. What is the formula for calculating expected frequencies in the chi-square test for independence?
(Total column/ N) Total row
A Spearman's correlation coefficient can range from _____ to _____
-1.00; 1.00
35. The critical cutoffs for a two-tailed Tukey HSD test comparing three group means with 11 within-groups degrees of freedom are:
-3.82 and 3.82
63. Pet preference was compared for four different types of animals (dogs, cats, birds, and fish), using a one-way within-groups ANOVA with seven participants. The standard error was calculated as 0.21. What are the critical cutoffs for the two-tailed Tukey HSD tests for these data, assuming a p level of 0.05, given the following groups' means: Dogs M = 4.43, Cats M = 4.18, Birds M = 2.73, Fish M = 4.07?
-4.0 and 4.0
79. Pet preference was compared for four different types of animals (dogs, cats, birds, and fish), using a one-way within-groups ANOVA with seven participants. The standard error was calculated as 0.21. What is the TukeyHSD value when comparing data for birds and fish given the following means for preference: Dogs M = 4.43, Cats M = 4.18, Birds M = 2.73, Fish M = 4.07?
-6.38
38. Using the Bonferroni post hoc test, to make all possible comparisons between the means of three groups while keeping the overall p level at 0.05, what should the p level be for each comparison?
0.017
33. If the p level is 0.05 and the null hypothesis is true, what is the probability of making a Type I error (i.e., that one will fail to reject the null hypothesis)?
0.05
115. For a study, a chi-square statistic of 1.82 was calculated. There were 45 participants in total, and 2 degrees of freedom for the first variable and 3 degrees of freedom for the second variable. What is the effect size?
0.142
88. For a study, a chi-square statistic of 4.42 was calculated. There were 87 participants in total, and 2 degrees of freedom for the first variable and 1 degree of freedom for the second variable. What is the effect size?
0.225
64. For the data in the source table, what is the effect size for this one-way within-groups ANOVA? Source SS df MS F Between-groups 12.159 3 4.053 2.98 Subjects 6.77 5 1.354 0.996 Within-groups 20.4 15 1.360 Total 39.329 23
0.373
74. For the data in the source table, what is the effect size for this one-way within-groups ANOVA? Source SS df MS F Between-groups 10.1 2 5.05 4.751 Subjects 7.4 4 1.85 1.740 Within-groups 8.5 8 1.063 Total 26 14
0.54
70. For the data in the source table, what is the effect size for this one-way within-groups ANOVA? Source SS df MS F Between-groups 39.52 2 19.76 Subjects 6.45 5 1.29 Within-groups 19.93 10 1.993 Total 53 17
0.849
19. If the p level is.0.05 and the null hypothesis is true, what is the probability of NOT making a Type I error (i.e., one will correctly fail to reject the null hypothesis)?
0.95
15. In a z test and a t test, when there is no difference between groups, the test statistic is equal to _____, but in the ANOVA, when there are no differences among groups, the test statistic is equal to _____
0;1
What is the formula for the Spearman's correlation coefficient
1-6(sigma D^2) divided by N(N^2-1)
95. Corsi et al. (2007) conducted a study of the factors mediating whether injection drug users enter a drug treatment program. One of the factors explored was marital status. The researchers found that 66 of 135 married (or partnered) drug users entered a treatment program and 67 of 185 single drug users entered a treatment program. What is the relative likelihood of entering a treatment program if a user is married compared to if he or she is single?
1.35
61. A one-way within-groups ANOVA is used when there are _____ than 2 independent variable(s) with two or _____ levels
1; more
106. In a study of simulated juror decision making, Braden-Maguire, Sigal, and Perrino (2005) investigated the type of verdict assigned by study participants after they read a 12-page summary of a case involving a battered woman who had shot and killed her husband. Of the 80 participants, 27 assigned a verdict of guilty, 49 a verdict of not guilty by reason of self-defense, and 4 a verdict of not guilty by reason of insanity. What are the degrees of freedom associated with this chi square?
2
The paired ranks for a Wilcoxon signed-rank test were: 1, - 1; 2, - 2; 5, - 3; 3, - 5; 4, - 4. What is the sample size for this test?
2
110. If an adjusted standardized residual is larger than _____, the observed frequency in that cell differs significantly from the expected frequency.
2.0
A sample of 10 men and 12 women are compared on their ranked life satisfaction. What is the critical cutoff for a two-tailed Mann-Whitney U test comparing these groups?
29
78. A dependent-samples t test is used when there are _____ groups, and a within-groups ANOVA is used when there are at least _____ groups
2; 3
92. In a 2006 study, Gortmake and colleagues surveyed 80 lesbian and gay students at a large Midwestern state university to assess their experiences and their perceptions of the campus climate regarding lesbians and gays. One of the questions the researchers were interested in was whether a person's "outness" depended on his or her class in school (freshman, sophomore, junior, or senior). All participants were classified as closeted or as out. What are the degrees of freedom associated with the chi-square analysis of these data
3
A chi-square test for goodness-of-fit for which there are 4 categories and 20 participants would have _____ degrees of freedom.
3
A researcher is transforming finishing times from a 5K race into ordinal data and has the following scores in minutes: 12.2, 16.5, 13.4, 17.8, 13.4, 13.4, and 18.6. If the researcher ranks from fastest to slowest, what would be the rank of the three people with a finish time of 13.4?
3
51. What is the critical cutoff for F at a p level of 0.05 if the following degrees of freedom were calculated for a one-way within-groups ANOVA: dfbetween = 4, dfsubjects = 4, dftotal = 24, dfwithin = 16?
3.01
83. What is the critical cutoff for F at a p level of 0.05 if the following degrees of freedom were calculated for a one-way within-groups ANOVA: dfbetween = 4, dfsubjects = 4, dftotal = 24, dfwithin = 16?
3.01
82. Determine the critical cutoff for F at a p level of 0.05 if the following degrees of freedom were calculated for a one-way within-groups ANOVA: dfbetween = 2, dfsubjects = 7, dftotal = 23, dfwithin = 14.
3.74
97. A researcher decides to examine whether people prefer milk chocolate or dark chocolate. A chi-square test for goodness-of-fit is conducted. What is the critical cutoff for a test with a p level of 0.05?
3.841
103. With a p level of 0.05, a chi-square test for goodness-of-fit for which there are 5 categories would have _____ degrees of freedom, and the critical value for the chi square would be _____
4,9,49
77. For the data in the source table, what is the F statistic of interest to researchers? Source SS df MS F Between-groups 10.1 2 5.05 Subjects 7.4 4 1.85 Within-groups 8.5 8 1.063 Total 26 14
4.75
114. A chi-square test for goodness-of-fit is conducted on a nominal variable with 4 levels. What is the critical cutoff for a test with a p level of 0.05?
7.815
93. In a 2006 study, Gortmake and colleagues surveyed 80 lesbian and gay students at a large Midwestern state university to assess their experiences and their perceptions of the campus climate regarding lesbians and gays. One of the questions the researchers were interested in was whether a person's "outness" depended on his or her class in school (freshman, sophomore, junior, or senior). All participants were classified as closeted or as out. What is the critical cutoff for this test, given a p level of 0.05?
7.815
54. Pet preference was compared for four different types of animals (dogs, cats, birds, and fish), using a one-way within-groups ANOVA with seven participants. The standard error was calculated as 0.21. What is the TukeyHSD value when comparing data for dogs and birds given the following means for preference: Dogs M = 4.43, Cats M = 4.18, Birds M = 2.73, Fish M = 4.07?
8.10
73. For the data in the source table, what is the F statistic of interest to researchers? Source SS df MS F Between-groups 39.52 2 19.76 Subjects 6.45 5 1.29 Within-groups 19.93 10 1.993 Total 53 17
9.92
A Mann-Whitney U test is used to compare two groups of 18 on ranked athleticism. Which of these U test statistics would be considered significant?
91
9. In which situation would it be necessary to use a between-groups ANOVA?
A researcher is interested in the effects of distraction on driving performance and randomly assigns participants to one of three distraction groups
23. Given a scale dependent variable and a nominal independent variable with three or more levels, a(n) _____ could be used to analyze the data
ANOVA
45. When computing Tukey HSD with samples of different sizes, what additional step must be performed?
Calculate a weighted sample size called a harmonic mean
44. The z, t, and F distributions have something in common—the numerator of the test statistic:
Contains a measure of difference among group means
A researcher wants to examine the relation between class rank and popularity among peers. Class rank is provided by the school and includes each student's rank in order. The researcher assesses popularity using a likability measure that provides scale data. What does the researcher need to do to the data before calculating a statistic using a nonparametric test
Convert scale data to original data
26. An F statistic calculated on 2 and 26 degrees of freedom equals 2.23. Which decision should be made about a hypothesis tested at the p = 0.05 level?
Fail to reject the null hypothesis and conclude no significant differences are indicated among the groups.
76. A one-way within-groups ANOVA on 2 and 15 degrees of freedom results in an F statistic of 3.12. What decision should be made about the hypothesis based on this statistic?
Fail to reject the null hypothesis because the F statistic does not exceed the critical cutoff
For the data in the source table, what decision can be made about the hypotheses being tested? Source SS df MS F Between-groups 12.159 3 4.053 Subjects 6.77 5 1.354 Within-groups 20.4 15 1.360 Total 39.329 23
Fail to reject the null hypothesis because the F statistic does not exceed the critical cutoff
Blake is interested in training for his first marathon and wants to determine whether the finishing place of non-elite marathon runners depends on the type of training program used. There are three training programs he is interested in comparing: Hal Higdon's, Jeff Galloway's, and Art Liberman's. Blake is able to track down 30 runners, 10 of whom have done each of the training programs. Blake asks the runners how they placed in the marathon. What statistic should he use to analyze his data?
Kruskal-Wallis H test
The nonparametric equivalent of the one-way between-groups ANOVA is the
Kruskal-Wallis H test.
A correlation of 0.56 is found between class rank and student likeability. What can be concluded based on this correlation
Low class ranks tend to be associated with low like ability ranks, and high class ranks tend to be associated with high ranks for like ability
32. The symbol for variance in ANOVA is
MS, which stands for mean squared
27. F is obtained by dividing _____ by _____
MSbetween; MSwithin
Does a person's letter grade in statistics depend on whether he or she is a member of a Greek organization? In three statistics classes, data is collected on the letter grades of students belonging to Greek organizations and of students who are not members. Which technique would be used to analyze the data
Mann-Whitney U test
Now that you are an adult, you decide to test one of the truisms passed along by your mother: "Cheaters never win in the end." You randomly assign a group of 20 children to either cheat or to play fair on a scavenger hunt. You then rank the children by how many items they were able to get during the scavenger hunt. Which technique would you use to analyze the data to determine whether cheaters finish differently than non-cheaters?
Mann-Whitney U test
The nonparametric equivalent of the independent-samples t test is the:
Mann-Whitney U test
Does a person's letter grade in statistics depend on whether he or she is a member of a Greek organization? In three statistics classes, data is collected on the letter grades of students belonging to Greek organizations and of students who are not members. Which of these is the null hypothesis for this study?
Members and nonmembers of greek organizations do not tend to differ in letter grades
A sample of 10 men and 12 women are compared on their ranked life satisfaction. Which of these is the null hypothesis for this study?
Men and Women do not tend to differ in ranked life satisfaction
What is the correct formula for between-groups degrees of freedom?
Ngroups - 1
A Spearman correlation of rs = -0.30 between birth order and IQ means that
People with lower birth orders tend to have higher IQs
71. Pet preference was compared for four different types of animals (dogs, cats, birds, and fish), using a one-way within-groups ANOVA with seven participants. The standard error was calculated as 0.21. Where are the significant effects for preference among these groups, given the following means for preference: Dogs M = 4.43, Cats M = 4.18, Birds M = 2.73, Fish M = 4.07?
Preference for birds is significantly lower than for the other three groups, and there are no other differences among the mean preferences.
The proportion of variance in the dependent variable that is accounted for by the independent variable is ____
R^2
49. An F statistic calculated on 3 and 48 degrees of freedom equals 4.23. Which decision should be made about a hypothesis tested at the p = 0.05 level?
Reject the null hypothesis and conclude there are differences among the groups.
65. For the data in the source table, what decision can be made about the hypotheses being tested? Source SS df MS F Between-groups 39.52 2 19.76 Subjects 6.45 5 1.29 Within-groups 19.93 10 1.993 Total 53 17
Reject the null hypothesis and conclude there are differences among the levels of the independent variable
For the data in the source table, what decision can be made about the hypotheses being tested? Source SS df MS F Between-groups 10.1 2 5.05 Subjects 7.4 4 1.85 Within-groups 8.5 8 1.063 Total 26 14
Reject the null hypothesis and conclude there are differences among the levels of the independent variable.
Three different ethnic groups are compared on their ranked language skills and an H statistic of 7.1 is computed. What conclusion could be made about a hypothesis test at a p level of 0.05?
Reject the null hypothesis and conclude there are differences among these groups for ranked language skills
11. MSbetween is obtained by dividing:
SSbetween by dfbetween.
50. MSwithin is obtained by dividing:
SSwithin by dfwithin.
The process of bootstrapping requires
Sampling with replacement
30. Lucille is interested in the effects of alcohol consumption on style of play while playing the videogame Sims. She asks a group of 15 college students to play Sims under one of the following conditions: no alcohol, 1 ounce of alcohol, 2 ounces of alcohol, or 3 ounces of alcohol. Lucille measures on a scale of 1 to 10 how prosocial the students' style of play is. After collecting the data, Lucille performs an ANOVA and finds that she can reject the null hypothesis. On this basis, what does Lucille know?
She knows that there is a difference among the groups somewhere, but she does not know where.
A researcher wants to examine the relation between class rank and popularity among peers. Class rank is provided by the school and includes each student's rank in order. The researcher assesses popularity using a likability measure that provides scale data. What statistic should be used to assess this relation
Spearman rank-order correlation coefficient
A researcher wants to examine the relation between class rank and popularity among peers. Class rank is provided by the school and includes each student's rank in order. The researcher assesses popularity using a likability measure that provides scale data. What statistic should be used to assess this relation?
Spearman rank-order correlation coefficient
The nonparametric equivalent of the Pearson correlation coefficient is the
Spearman rank-order correlation coefficient
The comparison distribution for the Wilcoxon signed-rank test is the _____ distribution
T
When transforming scale data to ordinal data, if two people have exactly the same score, what is their rank
They receive the average of the two ranks they would hold if the scores were different
The nonparametric equivalent of the paired-samples t test is the
Wilcoxon signed-ranked test
56. A one-way within-groups ANOVA on 3 and 28 degrees of freedom results in an F statistic of 3.94. What decision should be made about the hypothesis based on this statistic?
aReject the null hypothesis and conclude there are differences among the levels of the independent variable.
The expected frequencies across all cells of the chi square should:
always add up to the size of the sample
29. If the cutoff q statistic is 4.96, with a p level of 0.05, which of these would be significant?
an HSD of 5.2
If one rejects the null hypothesis when using the Kruskal-Wallis H test, then:
at least one of the groups differs significantly from another, but you do not know which one
47. Interested in the effects of different kinds of instruction on videogame performance, Martin asks 30 college freshmen to each play one hour of Ratchet and Klank. Participants are randomly assigned to one of three instruction groups: (1) complete the tasks as quickly as possible, (2) conserve as much health as possible (i.e., play more carefully), or (3) find gold bolts (worth lots of money in equipment and ammunition). If Martin averages the scores for each instruction group and then compares them, any differences in the means of the instruction groups reflect:
between-group variance
48. R^2, the effect size for ANOVA, is calculated as a ratio of
between-groups sums of squares to total sum of squares.
7. A measure of the differences among group means is:
between-groups variance
100. The appropriate statistic for analyzing data in a situation in which both the independent and dependent variables are nominal is a(n):
chi square
The H distribution for the Kruskal-Wallis H test is very close to the _____ distribution, so the latter is often used for determining the critical values for the Kruskal-Wallis H test
chi square
105. A college instructor is interested in whether assigning mandatory homework affects students' grades. Since she is currently teaching two sections of the same class, the instructor assigns homework to one of the classes and just recommends homework problems to the second class. Then she determines the number of people in each class that will receive an A, B, C, D, or F on the final exam. What type of statistical test should the instructor use to analyze her data?
chi-square test for independence
There is a different F distribution for every:
combination of sample size and number of samples
59. Pet preference was compared for four different types of animals (dogs, cats, birds, and fish), using a one-way within-groups ANOVA with seven participants. The standard error was calculated as 0.21. A significant F test indicates that there are differences between the groups. What post hoc tests are you most interested in performing given these group means: Dogs M = 4.43, Cats M = 4.18, Birds M = 2.73, Fish M = 4.07?
comparisons of preference for birds with the other groups, because the mean is noticeably lower
To calculate a Spearman rank-order correlation coefficient, first convert both variables to ranks. After that:
compute the difference between each pair of ranks
37. The z, t, and F distributions have something in common—the denominator of the test statistic:
contains a measure of difference within the various groups.
91. The table constructed for a chi-square test of independence is a _____ table
contingency
Order effects in a within-groups ANOVA can be resolved by using:
counterbalancing
The values in the cells of a chi-square test for goodness-of-fit are:
counts or frequencies
40. Changes in within-groups variance result in changes in the _____ of the F ratio.
denominator
22. If between-groups variance is much larger than within-groups variance, we infer that the sample means are _____ one another, and we _____ the null hypothesis.
different from; reject
39. Using the Bonferroni post hoc test, the overall probability of making a Type I error can be kept at a p level of 0.05 by:
dividing 0.05 by the number of comparisons you plan to make and using the result as the plevel for each comparison
20. The F ratio is calculated by
dividing a measure of between-groups variability by a measure of within-groups variability
112. The same formula is used to calculate the chi-square statistic in the chi-square test for goodness-of-fit and the chi-square test of independence. Which calculation differs along the way for these two tests?
expected frequencies
104. For a chi-square test, it is typically recommended that the minimum number of participants is
five times the number of cells
13. Within-groups degrees of freedom is calculated by
for each condition, subtracting 1 from the number of subjects in that group and then adding together the totals for all the groups
57. _____ degrees of freedom must be calculated in a within-groups ANOVA.
four
60. ___ sums of squares must be calculated in a within-groups ANOVA.
four
10. Violation of the assumption that samples are randomly selected affects researchers' ability to
generalize the results of a study beyond the sample
When there is one nominal variable, the appropriate statistical test to use is a chi-square test for:
goodness-of-fit
69. To calculate the total sum of square for the one-way within-groups ANOVA, each score's deviation from the _____ is squared and summed.
grand mean
111. In a study of simulated juror decision making, Braden-Maguire, Sigal, and Perrino (2005) investigated the type of verdict assigned by study participants after they read a 12-page summary of a case involving a battered woman who had shot and killed her husband. In particular, the researchers manipulated the race of the defendant (African American or Caucasian) and the type of abuse suffered (emotional or physical). The dependent variable was the number of guilty verdicts. What type of chi-square test should the researchers use to analyze these data?
independence
For two nominal variables, the appropriate statistical test to use is a chi-square test for:
independence
Does the number of points a person earns on the final exam in statistics depend on whether the person is a member of a Greek organization? In three statistics classes, data is collected on the final exam points of students belonging to Greek organizations and of students who do not belong. Which technique would be used to analyze the data?
independent-samples t test
42. Cohen's d cannot be used as a measure of effect size for ANOVA because:
it can only compare two means
16. According to Cohen's conventions, an R 2 of 0.19 is considered to be a(n) _____ effect size.
large
87. According to Cohen's conventions, an effect size of 0.29 for a one-way within-groups ANOVA is considered to be
large
98. Using Cohen's conventions for effect size, how would one label a Cramer's V = 0.30, if the row df = 3 and the column df = 3?
large
28. Homoscedasticity can be tested for by
making sure that the largest sample variance is no more than two times the smallest variance
85. A researcher wants to take advantage of the strengths of a within-groups design, but does not want to have each participant experience all levels of the independent variable. She can accomplish this through what other design option?
matched groups
46. the grand mean is the
mean of every score in the study, regardless of the sample
Bootstrapping is used on a sample of data with the following values: 520, 515, 480, 420, 610, 470, 420, and 630. The confidence interval created through bootstrapping will be centered around what value?
mean of the original sample
108. A chi-square test for independence is calculated on two variables, each with two degrees of freedom. An effect size of 0.23 is calculated. What size effect is this?
medium
8. According to Cohen's conventions, an R 2 of 0.07 is considered to be a(n) _____ effect size
medium
80. According to Cohen's conventions, an effect size of 0.056 for a one-way within-groups ANOVA is considered to be
medium
T If the p level is 0.05 and the null hypothesis is true, what is the probability of making a Type I error (i.e., that one will fail to reject the null hypothesis)?the less overlap there is among sample distributions, the:
more confident we are that the samples represent true differences in the population
43. The less overlap there is among sample distributions, the:
more confident we are that the samples represent true differences in the population.
What is the correct formula for degrees of freedom associated with the subjects sum of squares?
n-1
113. Legal researchers were interested in whether a rape defendant's perceived guilt depends on the type of argument introduced by his defense attorney. Researchers classified each defense by whether it introduced the idea that the female victim was asking for the encounter—the "she shouldn't have worn that short skirt" defense. In a simulated juror situation, the researchers counted the number of guilty verdicts "returned" by the 20 participating mock jurors. This number is a _____ dependent variable, which means that the data can be analyzed using a _____ test.
nominal; nonparametric
Melanie is interested in whether science fiction movies typically get higher star ratings (on a five-star scale) than dramas. What kind of statistical test could be used to address this question?
nonparametric test
36. Changes in between-groups variance result in changes in the _____ of the F ratio
numerator
102. A chi-square test for goodness-of-fit is an appropriate statistical test to use when the study has
one nominal dependent variable
58. Buying jeans can be a challenge for women. A local shop owner wants to be selective in what brands of jeans she carries in her store. She gets six of her closest friends to try five different pairs of jeans, with the requirement that they wear each pair for two whole days, without washing, and they rate the jeans at the end of the second day. What research design should she use to analyze her data?
one-way within-groups ANOVA
To use a nonparametric test despite having scale data, transform the data from scale to:
ordinal
Nonparametric tests are usually used when the sample data are
ordinal or extremely skewed
68. The one-way within-groups design can be viewed as an extension of which other research design because of its ability to analyze data from more groups?
paired-samples t test
66. There are some problems with a matched groups design, including that:
participant drop-out means data are discarded.
A Spearman correlation of rs = -0.30 between birth order and IQ means that:
people with lower birth orders tend to have higher IQs
81. A researcher studying weight loss among overweight teenage girls wants to use a matched groups design to assess the effectiveness of three different diets. On which variable is it MOST important to match the participants?
percent body fat
When graphing the results of a chi-square test it is more useful to graph _____ rather than _____.
proportions or percentages; frequencies
21. To evaluate Tukey's HSD, consult the _____ table.
q
17. The assumptions of ANOVA are that samples are selected:
randomly, the population distribution is normal, and the samples come from populations with equal variances.
41. A post hoc test is warranted when one:
rejects the null hypothesis and there are more than two groups.
52. A one-way within-groups ANOVA is also known as a _____ ANOVA.
repeated-measures
96. When using a nonparametric test (in contrast to a parametric hypothesis test) the:
risk of committing a Type II error is increased.
the process of bootstrapping requires
sampling with replacement
109. What is the correct formula for the chi-square statistic?
sigma(O1-E1)^2 divided by E1
6. According to Cohen's conventions, an R 2 of 0.02 is considered to be a(n) _____ effect size
small
84. According to Cohen's conventions, an effect size of 0.019 for a one-way within-groups ANOVA is considered to be:
small
When using the Wilcoxon signed-rank test, reject the null hypothesis only when the _____ of the two calculated statistics is equal to or _____ than the critical value
smaller; less
12. If there are only two samples, then the F distribution is the:
square of the t distribution
24. If there are only two samples and sample size is infinity, then the F distribution is the:
square of the z distribution
75. The _____ sum of squares is unique to the within-subjects design.
subject
67. Which degrees of freedom value is unique to the one-way within-groups ANOVA?
subjects
34. Between-groups degrees of freedom is calculated by:
subtracting 1 from the total number of groups in the study.
18. With two groups, the square root of F is equal to
t
62. Compared to a one-way between-groups ANOVA, the effect size calculation for the one-way ANOVA differs in
that variability due to subjects is removed from total variability in the denominator
One danger of reporting relative risk or relative likelihood information rather than frequencies is that:
the base rate occurrence of an event is not reported, and the data can be misleading
The assumptions of the Mann-Whitney U test are that
the data are ordinal, the participants are randomly selected, and ideally no ranks are tied
90. The adjusted standardized residual tells which of these?
the number of standard errors an observed frequency is from its expected frequency
94. When graphing the results of a chi-square study, it is important for the y-axis to depict
the scale of proportions from 0 to 1.0
Using a p level of 0.05, a researcher performed the Wilcoxon signed-rank test with a sample size of 16 and found that the sum of the ranks for positive differences was 36 and the sum of the ranks for negative differences was 100. Which statement accurately describes the results of the hypothesis test for these data?
the test statistic is larger than the critical cutoff, which is 29, so fail to reject the null hypothesis
31. If an F statistic is negative, which of these is true?
there has been a calculation error
99. A chi-square test for independence is an appropriate statistical test to use when the study has:
two nominal dependent variables
101. Chi-square tests for independence assess whether:
two nominal variables are independent for each other
The F ratio is a ratio of
two variances
One of the assumptions of the Mann-Whitney U test is that there are no ties. If there are ties in the data set:
use the Mann-Whitney U test if there are just a few ties as it is robust to violations of this assumption.
When F is significant
we do not know which specific means differ significantly.
55. In addition to hypothesis testing, post hoc tests are required as a way to assess:
where the significant differences exist among groups.
107. The chi-square test to use for two nominal variables is called the chi-square test for independence because one is assessing:
whether the effect of each variable is independent of the other variable.
53. In addition to hypothesis testing, effect size calculations are recommended as a way to assess
whether the significant differences found are large enough to matter
14. A measure of variability that is essentially an average of the sample variances is:
within-group variance
86. Dr. Sanders was interested in investigating the effects of stress on memory. He exposed participants to public speaking stress and room temperature stress and gave them a memory measure immediately after exposure to the two stressors. Dr. Sanders also gave participants the memory measure at baseline, when they first entered the research laboratory. Dr. Sanders hypothesized that participants' memories would be most affected by the two stressors compared to the baseline condition. What statistical test should Dr. Sanders use to test her hypothesis?
within-groups ANOVA
72. What types of designs are normally preferred to reduce variability by reducing individual differences?
within-groups design
25. The F statistic increases when:
within-groups variance decreases and between-groups variance increases.