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Biostatistics exam 2 study guide

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Quiz sobre Biostatistics exam 2 study guide, criado por Tyler Peterson em 12-04-2017.
Tyler Peterson
Quiz por Tyler Peterson, atualizado more than 1 year ago
Tyler Peterson
Criado por Tyler Peterson aproximadamente 7 anos atrás
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Resumo de Recurso

Questão 1

Questão
Which of the following is an example of a nonparametric test?
Responda
  • a z test
  • a paired t-test
  • chi-square test
  • confidence interval estimation

Questão 2

Questão
Which of the following is a statistical procedure used to test hypotheses about the discrepancy between the observed and expected frequencies in two or more nominal categories
Responda
  • related samples sign test
  • paired t-test
  • chi-square test
  • all of the above

Questão 3

Questão
A genetics researcher expects 1:1:1:1 across four groups to align with Mendelian ratios.. If 200 people are tested, then what is the expected frequency for each group?
Responda
  • 25 people
  • 50 people
  • 100 people
  • 200 people

Questão 4

Questão
A chi-square goodness-of-fit test shows that the frequencies observed fit well with those that were expected. Hence, the decision was to
Responda
  • reject the null hypothesis
  • retain the null hypothesis
  • no decision was made
  • accept the null hypothesis

Questão 5

Questão
The degrees of freedom for a chi-square goodness-of-fit test are [k=# categories, n=sample size]
Responda
  • k-1
  • n-1
  • (k1 - 1)(k2 - 1)
  • (k - 1)(n - 1)

Questão 6

Questão
As a general rule, the larger the degrees of freedom for a chi-square test
Responda
  • the smaller the critical value will be
  • the larger the critical value will be
  • the smaller the level of significance will be
  • the larger the level of significance will be

Questão 7

Questão
A researcher conducts a chi-square goodness-of-fit test in which k = 5 (k=# categories). What is the critical value for this test at a .05 level of significance?
Responda
  • 4
  • 5
  • 9.49
  • 11.07

Questão 8

Questão
A researcher conducts a chi-square goodness-of-fit test in which k = 3 and x (?) = 4.32. What is the decision for this test at a .05 level of significance?
Responda
  • Retain the null hypothesis
  • Reject the null hypothesis
  • There is not enough information to answer this question.

Questão 9

Questão
A chi-square goodness-of-fit test leads to a decision to retain the null hypothesis. Which of the following correctly explains this decision?
Responda
  • frequencies observed were significantly different from frequencies expected at each level of the categorical variable
  • frequencies observed were significantly different from frequencies expected across the levels of the categorical variable
  • frequencies observed were significantly different from frequencies expected within and between expected frequencies
  • Frequencies observed were statistically similar to the frequencies expected at each level of the categorical variable

Questão 10

Questão
When computing a chi-square goodness-of-fit test for a 2 x 2 table, the frequency expected in a given cell should never be less than
Responda
  • the sample size
  • the number of cells
  • the frequency observed
  • five

Questão 11

Questão
The degrees of freedom for a chi-square test for independence test are [k are categories, n are sample size]
Responda
  • k - 1
  • n - 1
  • (k1 - 1)(k2 - 1)
  • (k - 1)(n - 1)

Questão 12

Questão
A researcher tests whether levels of education and income levels are related. In this study, he observes the following frequencies. If he computes a chi-square test for independence at a .05 level of significance, then what is the decision for this test? Education Level High School Bachelor's Degree Graduate Degree Low Income 22 8 5 High Income 8 12 28
Responda
  • Education and income level are related
  • Education and income level are not related
  • Education and income level are independent
  • Both B and C are appropriate

Questão 13

Questão
To compute the expected frequencies for a chi-square test for independence, we use which of the following formulas?
Responda
  • k - 1
  • p(n)
  • (row total + column total)/grand total
  • (row total * column total)/grand total

Questão 14

Questão
If the expected frequencies equal to observed frequencies for a chi-square test for independence, what do we conclude?
Responda
  • the degrees of freedom for the test are equal to 0
  • the test statistic value is equal to 0
  • the frequencies observed fit well with the frequencies expected
  • both B and C

Questão 15

Questão
A researcher conducts two chi-square tests. The 2 2 chi-square was 2 = 3.82. The 2 3 chi-square was 2 = 5.02. Which chi-square test resulted in a decision to reject the null hypothesis at a .05 level of significance?
Responda
  • A) the 2 2 chi-square
  • B) the 2 3 chi-square
  • C) both chi-square tests results in a decision to reject the null hypothesis
  • D) none; both chi-square tests result in a decision to retain the null hypothesis

Questão 16

Questão
When assumptions regarding expected cell counts are not met, an alternative test to the chi-square test is:
Responda
  • McNemar’s test.
  • The Goodness of Fit test.
  • The Sign test.
  • Fisher’s Exact test.

Questão 17

Questão
17. The chi-square test assumes independence between observations. When the design is matched and we wish to compare two dichotomous variables, which test is appropriate?
Responda
  • A) McNemar’s test.
  • B) The Goodness of Fit test.
  • C) The Related Sample Sign test.
  • D) Fisher’s Exact test.

Questão 18

Questão
18. For an analysis of variance, the term “one-way” refers to
Responda
  • A) the number of factors in the design
  • B) the number of statistical tests in the design
  • C) the number of ways that the data can be analyzed
  • D) the direction that traffic should follow on a road

Questão 19

Questão
19. The term “between-subjects” refers to
Responda
  • A) observing the same participants in each group
  • B) observing different participants one time in each group
  • C) the type of post hoc test conducted
  • D) the type of effect size estimate measured

Questão 20

Questão
20. A lowercase k is used to denote
Responda
  • A) the number of groups in a study
  • B) the number of participants in a study
  • C) the number of levels of the factor in a study
  • D) both A and C

Questão 21

Questão
21. The source of variability associated with error variance in the one-way between-subjects ANOVA is called
Responda
  • A) between-groups variability
  • B) within-groups variability
  • C) degrees of freedom
  • D) both A and B

Questão 22

Questão
22. Without changing the value of error variance, the ________ the between-groups variability, the more likely we are to reject the null hypothesis.
Responda
  • A) larger
  • B) smaller
  • C) more homogeneous
  • D) less spread

Questão 23

Questão
23. What is the minimum number of groups that can be observed using the one-way between-subjects ANOVA design?
Responda
  • 1
  • 2
  • 3
  • 4

Questão 24

Questão
24. A researcher notes that the variability attributed to difference between group means is quite large. Which source of variation is the researcher referring to?
Responda
  • A) between-persons
  • B) within-groups
  • C) between-groups
  • D) error

Questão 25

Questão
25. ANOVA stands for,
Responda
  • A) analysis of variety
  • B) analysis of variable attributes
  • C) analysis of variance
  • D) association of novel operating variable analyses

Questão 26

Questão
26. The degrees of freedom for the between-groups variability is called
Responda
  • A) degrees of freedom numerator
  • B) degrees of freedom denominator
  • C) degrees of freedom between-groups
  • D) both A and C

Questão 27

Questão
27. The degrees of freedom for error is called
Responda
  • A) degrees of freedom error
  • B) degrees of freedom denominator
  • C) degrees of freedom within-groups
  • D) all of the above

Questão 28

Questão
28. A researcher compares differences in creatinine between participants in a three treatment groups. If she observes 15 participants in each group, then what are the degrees of freedom for the one-way between-subjects ANOVA?
Responda
  • A) (2, 12)
  • B) (3, 43)
  • C) (2, 42)
  • D) (3, 12)

Questão 29

Questão
29. A researcher conducts a study in which k = 5 and N = 80. What are the degrees of freedom between-groups for the one-way between-subjects ANOVA?
Responda
  • A) 4
  • B) 5
  • C) 75
  • D) 395

Questão 30

Questão
30. A researcher assigned participants (n = 8 per group) to three dose groups. Different participants were assigned to each group and then assessed for a specific biomarker. What is the critical value for the one-way between-subjects ANOVA at a .05 level of significance?
Responda
  • A) 3.07
  • B) 3.44
  • C) 3.47
  • D) 4.32

Questão 31

Questão
31. Which of the following is an assumption for computing a one-way between-subjects ANOVA?
Responda
  • A) The population being sampled from is normally distributed.
  • B) Participants were selected to participate using a random procedure.
  • C) One observation has no effect on the likelihood of another observation.
  • D) all of the above

Questão 32

Questão
32. Computing a one-way between-subjects ANOVA is appropriate when
Responda
  • A) different participants are observed one time in each of two or more groups for one factor
  • B) the same participants are observed in each of two or more groups for one factor
  • C) the levels of one or more factors are manipulated
  • D) all of the above

Questão 33

Questão
33. A researcher divides participants into groups that will engage in low, moderate, or intense levels of exercise. The total calories consumed by participants following the exercise are then recorded. What type of statistical design is appropriate for this study?
Responda
  • A) a related samples t test
  • B) a two-independent sample t test
  • C) a one-way between-subjects ANOVA
  • D) both B and C

Questão 34

Questão
34. Homogeneity of variance is an assumption for the one-way between-subjects ANOVA. What does this assumption mean?
Responda
  • A) that the population being sampled from is normally distributed
  • B) that participants are randomly selected to participate in a sample
  • C) that the variance is equal in each population from which samples are selected
  • D) that one observation has no effect on the likelihood of another observation

Questão 35

Questão
35. A researcher randomly assigned 16 rodents to experience one of four levels of shock (n = 4 per group) following the illumination of a visual cue. If SSB = 24 and SSW = 48, then what was the decision at a .05 level of significance for a one-way between-subjects ANOVA?
Responda
  • A) Reject the null hypothesis.
  • B) Retain the null hypothesis.
  • C) There is not enough information to answer this question.
  • D) Do not reject the null hypothesis.

Questão 36

Questão
36. A researcher assigns 21 subjects to 3 treatment groups. An equal number of participants are assigned to each group. If F = 4.08 for this study, then what was the decision at a .05 level of significance for a one-way between-subjects ANOVA?
Responda
  • A) Reject the null hypothesis.
  • B) Retain the null hypothesis.
  • C) There is not enough information to answer this question.
  • D) Do not reject the null hypothesis

Questão 37

Questão
37. A researcher conducts two studies on self-perception. In Study 1, 24 participants rate how positively they view themselves (on a 5-point scale) in one of three groups (n = 8 per group). In Study 2, the researcher conducts a similar study, except that k = 3 and n = 8. If SSB = 28 and SSE = 42 in both studies, then in which study will the decision be to reject the null hypothesis at a .05 level of significance for a one-way between-subjects ANOVA?
Responda
  • A) Study 1
  • B) Study 2
  • C) both
  • D) none

Questão 38

Questão
38. A researcher computes the following one-way between-subjects ANOVA table. State the decision at a .05 level of significance. (Hint: Complete the table first.) Source of Variation SS df MS F Between groups 32 4 Within groups (error) 45 Total 122
Responda
  • A) Reject the null hypothesis.
  • B) Retain the null hypothesis.
  • C) Accept the null hypothesis.
  • D) There is not enough information to answer this question.

Questão 39

Questão
39. A researcher computes the following one-way between-subjects ANOVA table for a study where k = 3 and n = 12. State the decision at a .05 level of significance. (Hint: Complete the table first.) Source of Variation SS df MS F Between groups 120 Within groups (error) Total 780
Responda
  • A) Reject the null hypothesis.
  • B) Retain the null hypothesis.
  • C) Accept the null hypothesis.
  • D) There is not enough information to answer this question.

Questão 40

Questão
40. In a study with four groups and 10 participants in each group, the sum of squares for the between-groups source of variation is 60. What is the value for the mean square between-groups in this study?
Responda
  • A) 10
  • B) 15
  • C) 20
  • D) 1.67

Questão 41

Questão
41. When the variability attributed to between-groups is equal to the variability attributed to error, then the value of the test statistic for a one-way between-subjects ANOVA is,
Responda
  • A) Equal to 0.
  • B) Equal to 1.
  • C) Significant at any sample size.
  • D) Undefined in that the test statistic cannot be computed in this case.

Questão 42

Questão
42. Following a significant one-way between-subjects ANOVA in which k > 2, what is the next appropriate step?
Responda
  • A) Summarize the data; no further tests are required.
  • B) Interpret the data; no further tests are required.
  • C) Conduct post hoc tests.
  • D) both A and B

Questão 43

Questão
43. Which of the following is not a post hoc test for a one-way between-subjects ANOVA?
Responda
  • A) F test for equal variance
  • B) Fisher's LSD test
  • C) Tukey's HSD test
  • D) Bonferroni test

Questão 44

Questão
44. Which of the following post hoc tests is associated with the greatest power to detect an effect?
Responda
  • A) Schaffé test
  • B) Tukey's HSD test
  • C) Bonferroni test
  • D) Fisher's LSD test

Questão 45

Questão
45. Which of the following post hoc tests is associated with the least power to detect an effect?
Responda
  • A) Fisher's LSD test
  • B) Tukey's HSD test
  • C) Studentized Newman-Keuls
  • D) None; each post hoc test is associated with the same power to detect an effect.

Questão 46

Questão
46. Post hoc tests are computed
Responda
  • A) Prior to conducting a hypothesis test.
  • B) To determine which set of degrees of freedom can be attributed to the variability between-groups.
  • C) Following a significant ANOVA test to make pairwise comparisons.
  • D) to determine if groups means differ, even for tests in which the decision is to retain the null hypothesis.

Questão 47

Questão
47. The following is a summary of a one-way between-subjects ANOVA: F(2, 37) = 3.42, p < .05. How many pairwise comparisons need to be made for this ANOVA result?
Responda
  • A) 2
  • B) 3
  • C) 4
  • D) 12

Questão 48

Questão
48. The following is a summary of a one-way between-subjects ANOVA: F(2, 37) = 3.42, p < .05. How many participants were observed in this study?
Responda
  • A) 12
  • B) 37
  • C) 40
  • D) 39

Questão 49

Questão
49. The Kruskal-Wallis test is the nonparametric analog to the
Responda
  • A) one sample z test for a single population mean.
  • B) two independent samples t test.
  • C) one-way ANOVA F test.
  • D) paired t test.

Questão 50

Questão
50. The Kruskal-Wallis test can be used to:
Responda
  • A) compare a ranked outcome by race group (W, AA, Other).
  • B) compare a skewed continuous variable by a categorical variable with four levels.
  • C) compare an interval/ratio variable across more than two groups
  • D) All of the above

Questão 51

Questão
51. The Kruskal-Wallis test relies on:
Responda
  • A) ranked data
  • B) raw data
  • C) mean values
  • D) all of the above

Questão 52

Questão
52. The null hypothesis for the Kruskal-Wallis test is
Responda
  • A) the difference in ranks for the groups do not differ
  • B) the median values for the groups do not differ
  • C) the sum of the ranks in each group do not differ
  • D) the sum of the ranks in each group do differ

Questão 53

Questão
53. The test statistic used for the Kruskal-Wallis test follows which distribution?
Responda
  • A) the chi-square distribution with (k-1) degrees of freedom
  • B) the t distribution with (k-1) degrees of freedom
  • C) the F distribution with (1, k-1) degrees of freedom
  • D) the standard normal distribution

Questão 54

Questão
54. A post-hoc test that can be used following a significant Kruskal-Wallis test is:
Responda
  • A) Tukey’s LSD test
  • B) Bono U2 test
  • C) Dunns Q test
  • D) Duncin’s HSD test

Questão 55

Questão
55. The correlation coefficient is used to measure the ________ and ________ of the linear relationship between two factors.
Responda
  • A) date; time
  • B) mean; variance
  • C) significance; effect size
  • D) strength; direction

Questão 56

Questão
56. The correlation coefficient ranges from -1.0 to +1.0, with values closer to ±1.0 indicating
Responda
  • A) a more positive relationship between two factors
  • B) a stronger relationship between two factors
  • C) that two factors are less likely to be related
  • D) that the correlation is due to outliers

Questão 57

Questão
57. Which of the following indicates the strongest correlation?
Responda
  • A) r = -0.57
  • B) r = +0.78
  • C) r = -0.90
  • D) r = +0.88

Questão 58

Questão
58. The following graphs display the data points for two linear correlations. Based on the information provided in these graphs, ________ displays a negative correlation and ________ displays a stronger correlation.
Responda
  • A) Graph A; Graph B
  • B) Graph B; Graph A
  • C) Graph A; Graph A
  • D) Graph B; Graph B

Questão 59

Questão
59. The numerator of the correlation coefficient measures the extent to which two variables
Responda
  • A) vary together
  • B) vary independently
  • C) covary
  • D) both A and C

Questão 60

Questão
60. A researcher measures the following correlation between cups of coffee consumed daily and daily work schedule. Which description best explains the relationship between these two factors?
Responda
  • A) The more a person works, the more coffee he or she tends to drink.
  • B) The less a person works, the more coffee he or she tends to drink.
  • C) The more a person works, the less coffee he or she tends to drink.
  • D) No linear pattern is evident.

Questão 61

Questão
61. The denominator of the correlation coefficient measures the extent to which two variables
Responda
  • A) vary together
  • B) vary independently
  • C) covary
  • D) both A and C

Questão 62

Questão
62. The correlation coefficient measures the extent to which changes in one factor are _______ in a second factor.
Responda
  • A) related to changes
  • B) causing changes
  • C) causing variability
  • D) all of the above

Questão 63

Questão
63. A researcher measures the relationship between narcissism and willingness to help. If SSXY = 240, SSX = 320, and SSY = 410, then what is the value of the correlation coefficient?
Responda
  • A) 0.002
  • B) 0.02
  • C) 0.66
  • D) 0.69

Questão 64

Questão
64. A researcher measures the relationship between two variables, X and Y. If SSXY = 340 and SSXSSY = 320,000, then what is the value of the correlation coefficient?
Responda
  • A) 0.32
  • B) 0.34
  • C) 0.60
  • D) almost a zero correlation

Questão 65

Questão
65. Suppose a correlation is computed in each of two samples. If the value of SSXY is the same in each sample, and √SSXSSY is larger in Sample 1, then in which sample will the value of the correlation coefficient be larger?
Responda
  • A) Sample 1
  • B) Sample 2
  • C) None; the correlation coefficient will be the same in both samples.
  • D) There is not enough information to answer this question.

Questão 66

Questão
66. A researcher measures the following correlation: r = -0.21. What is the value of the coefficient of determination?
Responda
  • A) 0.04
  • B) -0.04
  • C) 0.42
  • D) -0.42

Questão 67

Questão
67. The assumption that there is an equal variance or scatter of data points dispersed along the regression line is referred to as
Responda
  • A) normality
  • B) linearity
  • C) homoscedasticity
  • D) restriction of range

Questão 68

Questão
68. What is the problem with the following data for computing a correlation? Factor 1 Factor 2 3 3 3 3 3 3 3 3 3 3
Responda
  • A) The correlation coefficient will equal 0 because it violates the assumption of normality.
  • B) The correlation coefficient will equal 1.0 because it violates the assumption of normality.
  • C) The correlation coefficient will equal 0 because it violates the assumption of linearity.
  • D) The correlation coefficient will equal 1.0 because it violates the assumption of linearity

Questão 69

Questão
69. The normality assumption states that the population of X and Y scores form a bivariate (“two variable”) normal distribution, such that
Responda
  • A) the population of X and Y scores are normally distributed
  • B) for each X score, the distribution of Y scores is normally distributed
  • C) for each Y score, the distribution of X scores is normally distributed
  • D) all of the above

Questão 70

Questão
70. Which of the following is the assumption that the best way to describe the pattern of data is using a straight line?
Responda
  • A) normality
  • B) linearity
  • C) homoscedasticity
  • D) restriction of range

Questão 71

Questão
71. Which of the following is a limitation for interpreting a correlation?
Responda
  • A) Correlations do not demonstrate cause-and-effect.
  • B) Outliers can change the direction and/or strength of the correlation.
  • C) Conclusions should not be drawn beyond the range of scores measured.
  • D) all of the above

Questão 72

Questão
72. An unanticipated variable not accounted for in a research study that could be causing or associated with observed changes in one or more measured variables is called
Responda
  • A) reverse causality
  • B) restriction of range
  • C) a confound variable
  • D) homoscedasticity

Questão 73

Questão
73. A researcher observes a correlation of values from 2 to 10 points and draws conclusions about the full range of values in the population from 0 to 21 points. Which limitation for correctly interpreting a correlation coefficient did the researcher violate?
Responda
  • A) reverse causality
  • B) restriction of range
  • C) a confound variable
  • D) homoscedasticity

Questão 74

Questão
74. Outliers can change the _____ of a correlation.
Responda
  • A) direction
  • B) strength
  • C) sign (+, -)
  • D) all of the above

Questão 75

Questão
75 A correlation coefficient can ______ demonstrate cause.
Responda
  • A) always
  • B) never
  • C) mostly
  • D) intermittently

Questão 76

Questão
76. The Spearman rank-order correlation coefficient is a measure of the direction and strength of the linear relationship between two ________ variables.
Responda
  • A) nominal
  • B) ordinal
  • C) interval
  • D) ratio

Questão 77

Questão
77. The appropriate correlation coefficient for measuring the direction and strength of the linear relationship between two ranked or ordinal variables is
Responda
  • A) the Spearman correlation coefficient
  • B) the point-biserial correlation coefficient
  • C) the phi correlation coefficient
  • D) none of the above

Questão 78

Questão
78. A researcher measures the correlation in rankings for a sample of restaurants and consumers' rankings of their favorite restaurants. If D2 = 96 and n = 12, then what is the value of the correlation coefficient?
Responda
  • A) 0.07
  • B) 0.34
  • C) 0.66
  • D) 0.94

Questão 79

Questão
79. A researcher measures the correlation of the time it take participants to complete two tasks purported to measure the same cognitive skill. Participant times are converted to ranks from fastest to slowest. If D2 = 165 and n = 20, then what is the decision for this correlation test?
Responda
  • A) Retain the null hypothesis.
  • B) Reject the null hypothesis.
  • C) There is not enough information to answer this question.

Questão 80

Questão
80. To summarize correlations, we report:
Responda
  • A) the strength of the correlation
  • B) the direction of the correlation
  • C) the p value
  • D) all of the above

Questão 81

Questão
81. Which of the following would not be reported for a correlation?
Responda
  • A) the sample size
  • B) the coefficient of determination
  • C) the critical values for each test
  • D) the strength and direction of the correlation

Questão 82

Questão
82. Select the description below that identifies the following correlation: r = .28, p < .01.
Responda
  • A) the correlation is positive
  • B) the correlation is statistically significant
  • C) the coefficient of determination is .08
  • D) all of the above

Questão 83

Questão
83. A researcher measures the extent to which time spent watching educational preschool television programming predicts success in school. Which variable is the outcome variable in this example?
Responda
  • A) educational preschool television
  • B) type of television programming
  • C) success in school
  • D) time spent in school

Questão 84

Questão
84. A researcher measures the extent to which the speed at which people eat (in minutes) predicts calorie intake (in kilocalories). Which factor is the predictor variable in this example?
Responda
  • A) the speed at which people eat
  • B) calorie intake
  • C) minutes and kilocalories
  • D) all of the above

Questão 85

Questão
86. Which of the following is used to determine the linear equation that “best fits” a set of data points?
Responda
  • A) correlational analysis
  • B) analysis of variance
  • C) analysis of regression
  • D) method of least squares

Questão 86

Questão
85. Linear regression describes the extent to which _______ predicts ________.
Responda
  • A) X; Y
  • B) the predictor variable; the outcome variable
  • C) the known variable; the to-be-predicted variable
  • D) all of the above

Questão 87

Questão
87. Which of the following is used to determine the significance of predictions made by a best fitting linear equation?
Responda
  • A) correlational analysis
  • B) analysis of variance
  • C) analysis of regression
  • D) method of least squares

Questão 88

Questão
88. A researcher reports the following equation for a best-fitting straight line to a set of data points: Y = -1.01X + 3.24. Which value is the y-intercept?
Responda
  • A) Y
  • B) X
  • C) ñ1.01
  • D) 3.24

Questão 89

Questão
89. A researcher reports the following equation for a best-fitting straight line to a set of data points: Y = 0.48X + 12.03. Which value is the slope?
Responda
  • A) Y
  • B) 0.48
  • C) 12.03
  • D) The slope is not given in this equation

Questão 90

Questão
90. If SSXY = -16.32 and SSX = 40.00 for a set of data points, then what is the value of the slope for the best-fitting linear equation?
Responda
  • A) -0.41
  • B) -2.45
  • C) positive
  • D) There is not enough information; you would also need to know the value of SSY.

Questão 91

Questão
91. If b = -0.57, My = 2.75, and Mx = 5.25 for a set of data points, then what is the value of the y-intercept for the best-fitting linear equation?
Responda
  • A) 0.24
  • B) 11.68
  • C) -0.24
  • D) 5.74

Questão 92

Questão
92. Which of the following is not needed to compute the y-intercept using the method of least squares?
Responda
  • A) My
  • B) Mx
  • C) Mxy
  • D) the slope

Questão 93

Questão
93. Which of the following is not needed to compute the slope using the method of least squares?
Responda
  • A) SSY
  • B) SSX
  • C) SSXY

Questão 94

Questão
94. A researcher reports the following regression equation for two variables, X and Y: Y = 5.10X - 1.50. If X = 2.30, then what is the value of Y-hat?
Responda
  • A) 10.23
  • B) 11.73
  • C) 13.23

Questão 95

Questão
95. Using an analysis of regression, the variability in Y that is predicted by X is measured by the
Responda
  • A) regression variation
  • B) residual variation
  • C) correlation coefficient
  • D) coefficient of determination

Questão 96

Questão
96. Using an analysis of regression, the variability in Y that is associated with error is measured by the
Responda
  • A) regression variation
  • B) residual variation
  • C) correlation coefficient
  • D) coefficient of determination

Questão 97

Questão
97. Both sources of variation in an analysis of regression measure the variability in
Responda
  • A) X and Y
  • B) X only
  • C) Y only

Questão 98

Questão
98. The more that the variability in ____ is associated with regression variation, the more likely it is that X predicts Y.
Responda
  • A) XY
  • B) X
  • C) Y
  • D) all of the above

Questão 99

Questão
99. Which of the following statements is true regarding the sources of variation present in an analysis of regression?
Responda
  • A) Regression variation measures variability in X, whereas residual variation measures variability in Y.
  • B) The closer that data points fall to the regression line, the more the variance in Y will be attributed to regression variation.
  • C) There are three sources of variation in an analysis of regression: regression variance, residual variance, and error variance.
  • D) When most of the variability in Y is associated with residual variation, then X predicts Y.

Questão 100

Questão
100. The degrees of freedom associated with regression variation are equal to
Responda
  • A) the number of predictor variables
  • B) the number of predictor variables minus one
  • C) n -1
  • D) n - 2

Questão 101

Questão
101. The degrees of freedom associated with residual variation are equal to
Responda
  • A) the number of predictor variables
  • B) the number of predictor variables minus one
  • C) n - 1
  • D) n - 2

Questão 102

Questão
102. If the coefficient of determination is 0.32 and SSY = 150, then what is the sum of squares residual for an analysis of regression?
Responda
  • A) 48
  • B) 102
  • C) 150
  • D) There is not enough information to answer this question.

Questão 103

Questão
103. If the coefficient of determination is 0.30 and the sum of squares regression for an analysis of regression is 210, then what is the value of SSY?
Responda
  • A) 210
  • B) 300
  • C) 490
  • D) 700

Questão 104

Questão
104. In a sample of 22 participants, suppose we conduct an analysis of regression with one predictor variable. If F = 4.07, then what is the decision for this test at a .05 level of significance?
Responda
  • A) X significantly predicts Y.
  • B) X does not significantly predict Y.
  • C) There is not enough information to answer this question.

Questão 105

Questão
105. A researcher computes the following analysis of regression table. Based on the data given, what is the decision for this test at a .05 level of significance? (Note: Complete the table first.) Source of Variation SS df MS F Regression 1 28 Residual Total 118 19
Responda
  • A) X significantly predicts Y.
  • B) X does not significantly predict Y.
  • C) There is not enough information to answer this question.

Questão 106

Questão
106. An estimate of the standard deviation or distance that data points fall from the regression line is measured by the
Responda
  • A) sum of squares
  • B) standard error of estimate
  • C) criterion variable
  • D) predictor variable

Questão 107

Questão
107. The standard error of estimate is used as a measure of the ________ in predictions using the equation of a regression line.
Responda
  • A) linearity
  • B) appropriateness
  • C) accuracy
  • D) certainty

Questão 108

Questão
108. What is the computation for the standard error of estimate?
Responda
  • A) the square root of the mean square regression
  • B) the square root of the mean square residual
  • C) the mean square regression, squared
  • D) the mean square residual, squared

Questão 109

Questão
109. A researcher computes a perfect negative correlation, in which each data point falls exactly on the regression line. In this example, the value of the standard error of estimate will be
Responda
  • A) less than 0
  • B) greater than 0
  • C) equal to 0
  • D) There is not enough information to answer this question

Questão 110

Questão
110. A researcher computes an analysis of regression in which MSE = 0.82. What is the value of se in this example?
Responda
  • A) 0.67
  • B) 0.82
  • C) 0.91
  • D) There is not enough information to answer this question.

Questão 111

Questão
111. A researcher computes the following analysis of regression table. Based on the data given, what is the value of the standard error of estimate? (Note: Complete the table first.) Source of Variation SS Df MS F Regression 28 1 5.60 Residual Total 118 19
Responda
  • A) 2.24
  • B) 5.00
  • C) 5.74
  • D) 8.49

Questão 112

Questão
112. Multiple regression is a statistical method that includes ____ predictor variable(s) in the equation of the regression line.
Responda
  • A) zero
  • B) one
  • C) two
  • D) two or more

Questão 113

Questão
113. A statistical method that includes two or more predictor variables in the equation of a regression line to predict changes in a criterion variable is called
Responda
  • A) analysis of variance
  • B) standard error of estimate
  • C) residual regression
  • D) multiple regression

Questão 114

Questão
114. One key advantage for including multiple predictor variables in the equation of a regression line is that it allows you to
Responda
  • A) detect mean differences between groups for each criterion variable
  • B) detect the extent to which two or more predictor variables interact
  • C) show cause-and-effect because many predictor variables are added
  • D) all of the above

Questão 115

Questão
115. Which of the following equations is appropriate for a linear regression with three predictor variables?
Responda
  • Y' = bX + a
  • Y' = b1X1 + b2X2 + a
  • Y' = b1X1 + b2X2 + b3X3 + a
  • Y' = b1X1 + b2X2 + b3X3 + b4X4 + a

Questão 116

Questão
116. For a multiple regression analysis with 2 and 12 degrees of freedom, MS regression is 135 and MS residual is 15. What is the decision for this test?
Responda
  • A) reject the null hypothesis; the predictive variability of two predictor factors are significant
  • B) retain the null hypothesis; the predictive variability of two predictor factors are not significant
  • C) reject the null hypothesis; the predictive variability of one predictor factor is significant
  • D) retain the null hypothesis; the predictive variability of one predictor factor is significant

Questão 117

Questão
117. The value of b1 and b2 are referred to as,
Responda
  • A) unstandardized beta coefficients
  • B) standardized beta coefficients
  • C) regression variation
  • D) residual variation

Questão 118

Questão
118. To standardize the beta coefficients, we first,
Responda
  • A) analyze the significance of each data point
  • B) analyze the residual variation
  • C) convert the original data to standardized z scores
  • D) compute the standard error of estimate

Questão 119

Questão
119. The equation for the standardized regression equation is,
Responda

Questão 120

Questão
120. In addition to evaluating the significance of a multiple regression equation, we also should consider:
Responda
  • A) the significance of the residual variability
  • B) the complexity of the correlation coefficient
  • C) the relative contribution of each factor
  • D) the significance of each individual data point

Questão 121

Questão
121. If F = 2.04 for the relative contribution of one factor, then what is this value when converted to a t statistic?
Responda
  • A) 2.04
  • B) 1.43
  • C) 4.16
  • D) The conversion is not possible

Questão 122

Questão
122. To summarize any type of regression analysis, we report each of the following except the,
Responda
  • A) test statistic
  • B) degrees of freedom
  • C) p value
  • D) critical values

Questão 123

Questão
123. The scores or data points for a regression analysis are typically reported in,
Responda
  • A) a scatter plot
  • B) a bar chart
  • C) a pie chart
  • D) all of the above

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