Exam 4 (for Final)
A researcher conducts a chi-square goodness-of-fit test in which k = 3 and = 4.32. What is the decision for this test at a .05 level of significance? A) Retain the null hypothesis. B) Reject the null hypothesis. C) There is not enough information to answer this question.
A
A researcher measures the correlation of the time it takes participants to complete two tasks purported to measure the same cognitive skill. Participant times are converted to ranks from fastest to slowest. If = 165 and n = 20, then what is the decision for this correlation test? A) Reject the null hypothesis because the calculated value exceeds the critical value. B) Reject the null hypothesis because the critical value exceeds the calculated value. C) Retain the null hypothesis because the calculated value exceeds the critical value. D) Retain the null hypothesis because the critical value exceeds the calculated value.
A
A researcher reports the following results for a chi-square test: (1) = 5.386, p < .05 (V = 0.224). If this test were a test for independence, then how many groups (cells) were observed? A) 4 B) 2 C) 1 D) 3
A
Many nonparametric tests are called ________ because they make no assumptions regarding the shape of the distribution in the population. A) distribution-free tests B) skewed-distribution tests C) parametric tests D) significance-free tests
A
The point-biserial correlation coefficient is a measure of the direction and strength of the linear relationship between two variables, where A) one is continuous, and one is dichotomous B) both variables are on an ordinal scale C) one is at interval level or higher and one is ordinal D) both variables are on a nominal scale
A
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? GRAPH A) The more a person works, the less coffee he or she tends to drink. B) The more a person works, the more coffee he or she tends to drink. C) The less a person works, the more coffee he or she tends to drink. D) No linear pattern is evident.
B
If the expected frequencies equal to observed frequencies for a chi-square test for independence, what do we conclude? A) the degrees of freedom for the test are equal to 0 B) the test statistic value is equal to 0 C) the frequencies observed fit well with the frequencies expected D) both B and C
B
The appropriate correlation coefficient for measuring the direction and strength of the linear relationship between one continuous and one dichotomous variable is A) the Spearman rank-order correlation coefficient B) the point-biserial correlation coefficient C) the phi correlation coefficient D) none of the above
B
We convert r to a chi-square statistic for which of the following correlation tests? A) Spearman B) phi C) point-biserial D) Pearson
B
A researcher computes a 2 × 2 chi-square test for independence. What is the critical value for this test at a .05 level of significance? A) 5.99 B) 7.81 C) 3.84 D) 6.64
C
A researcher computes a 2 × 3 chi-square test for independence. What is the critical value for this test at a .05 level of significance? A) 7.81 B) 3.84 C) 5.99 D) 12.59
C
A researcher computes a 3 × 5 chi-square test for independence. What are the degrees of freedom for this test? A) 15 B) 3 C) 8 D) 5
C
A researcher measures the following correlation between cost of produce and number of units sold. Which description best explains the relationship between these two factors? GRAPH A) Less expensive produce is associated with a decreased number of units sold. B) As the cost of produce increases, so also do the number of units sold. C) Less expensive produce is associated with an increased number of units sold. D) No linear pattern is evident.
C
The Friedman test is used as a nonparametric alternative to which parametric test? A) related samples t-test B) one-way between-subjects ANOVA C) one-way within-subjects ANOVA D) two-independent sample t-test
C
The appropriate correlation coefficient for measuring for the direction and strength of the linear relationship between two dichotomous variables is A) the Spearman rank-order correlation coefficient B) the point-biserial correlation coefficient C) the phi correlation coefficient D) none of the above
C
Which of the following indicates the strongest correlation? A) r = +0.78 B) r = +0.88 C) r = -0.90 D) r = -0.57
C
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? A) one-way ANOVA B) analysis of regression C) chi-square test D) all of the above
C
A chi-square goodness-of-fit test leads to a decision to retain the null hypothesis. Which of the following correctly explains this decision? A) frequencies observed were significantly different from frequencies expected across the levels of the categorical variable B) frequencies observed were significantly different from frequencies expected within and between expected frequencies C) frequencies observed were significantly different from frequencies expected at each level of the categorical variable D) Frequencies observed were statistically similar to the frequencies expected at each level of the categorical variable
D
A psychologist tests whether cravings for heroin and relapse are independent. The following table lists the observed frequencies, with the expected frequencies listed in parentheses. Calculate chi-square for these data. Chi-square = Relapse Yes No Cravings Yes 22 (17.07) 11 (15.93) 33 No 8 (12.93) 17 (12.07) 25 30 28 N=58 A) -6.84 B) 0 C) 2.62 D) 6.84
D
A researcher computes a 4 × 6 chi-square test for independence with a sample of 120 participants, with = 14.79. What is the effect size for this result? A) 0.12 B) 0.35 C) 0.04 D) 0.20
D
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? A) both chi-square tests results in a decision to reject the null hypothesis B) the 2 × 2 chi-square C) the 2 × 3 chi-square D) none; both chi-square tests result in a decision to retain the null hypothesis
D
A researcher selects a sample of 80 people and records the frequency of participants choosing a low, moderate, or high calorie dessert in a buffet. What are the degrees of freedom for this chi-square goodness-of-fit test? A) 79 B) 3 C) 80 D) 2
D
D
D
Imagine you are a journal editor. A researcher reports means and standard deviations for groups for a study that required running a chi-square test. Is there a problem? If so, what is it? A) There's no problem. B) It is meaningful to calculate means for chi-square data, but not standard deviations. C) It's not meaningful to calculate means and SDs for chi-square data because the data represent rank-orderings on the dependent variable. D) It's not meaningful to calculate means and SDs for chi-square data because the data represent frequency counts.
D
The assumption that there is an equal variance or scatter of data points dispersed along the regression line is referred to as A) restriction of range B) linearity C) normality D) homoscedasticity
D
The assumptions for performing Pearson r test are A) linearity B) homoscedasticity C) normality (for example, for variable x and for variable y) D) all of the above
D
The normality assumption states that the population of X and Y scores form a bivariate ("two variable") normal distribution, such that A) for each Y score, the distribution of X scores is normally distributed B) the population of X and Y scores are normally distributed C) for each X score, the distribution of Y scores is normally distributed D) all of the above
D
The numerator of the correlation coefficient measures the extent to which two variables A) vary together B) vary independently C) covary D) both A and C
D
The sign test is used as a nonparametric alternative to which parametric test? A) one-sample t-test B) two-independent sample t-test C) related samples t-test D) both A and C
D
Which of the following is an example of a parametric test? A) one-sample t-test B) Pearson correlation C) analysis of variance D) all of the above
D
A researcher records the frequency of participants selecting one of four new slogans for an advertising campaign. If it was expected that among 200 people polled there would be no preference for any one slogan, then what was the expected frequency for each slogan. A) 50 people B) 100 people C) 25 people D) 200 people
A
A chi-square goodness-of-fit test shows that the frequencies observed fit well with those that were expected. Hence, the decision was to A) reject the null hypothesis B) retain the null hypothesis C) no decision was made
B
Which of the following measures of effect size can be reported with a 3 × 4 chi-square test for independence? A) the phi coefficient B) Cramer's V C) proportion of variance D) all of the above
B
The Spearman rank-order correlation coefficient is a measure of the direction and strength of the linear relationship between two ________ variables. A) nominal B) ratio C) ordinal D) interval
C
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? A) reverse causality B) a confound variable C) homoscedasticity D) restriction of range
D
The formula for the Spearman correlation coefficient was derived from the formula for___________________________________________________________ A) Two way between groups ANOVA B) chi-square C) Krabby patties (this is not the correct answer) D) Pearson r
D
Which of the following is a key assumption for a chi-square goodness-of-fit test? A) The variance between groups is equal. B) The proportion in each cell is equal to zero. C) There is no mean difference between groups. D) The observed frequencies are independently recorded in each cell.
D
Which of the following would not be reported for a correlation? A) the coefficient of determination B) the sample size C) the strength and direction of the correlation D) the critical values for each test
D
When computing a chi-square goodness-of-fit test, the frequency expected in a given cell should never be less than A) five B) 100 C) the sample size D) the number of cells
A
A scientist finds two results. Result #1 is that higher education is associated with a larger annual income. Result #2 is that fewer calories consumed is associated with less visits to the doctor. How would you characterize these two results? A) Result #1 shows a positive correlation and result #2 shows a negative correlation. B) Result #1 shows a negative correlation and result #2 shows a positive correlation. C) Both results show a negative correlation. D) Both results show a positive correlation.
D
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 A) reverse causality B) homoscedasticity C) restriction of range D) a confound variable
D
As a general rule, the larger the degrees of freedom for a chi-square test, A) the smaller the critical value will be B) the smaller the level of significance will be C) the larger the level of significance will be D) the larger the critical value will be
D
Correlations can be depicted in a graph called a _______________ A) continuation plot B) bar chart C) pie chart D) scatter plot
D
A correlation coefficient can ______ demonstrate cause. A) always B) never C) mostly D) intermittently
B
Which of the following is recorded using a chi-square goodness-of-fit test and a chi-square test for independence? A) variance B) frequency observed C) frequency expected D) both B and C
D
A researcher measures the relationship between narcissism and willingness to help. If = 240, = 320, and = 410, then what is the value of the correlation coefficient? A) 0.66 B) 0.002 C) 0.02 D) 0.69
A
A researcher measures the relationship between two variables, X and Y. If = 340 and = 320,000, then what is the value of the correlation coefficient? A) 0.60 B) 0.34 C) almost a zero correlation D) 0.32
A
What is a key distinction between parametric tests and nonparametric tests in terms of scales of measurement? A) Parametric tests are used for interval and ratio data, whereas nonparametric tests are used for nominal and ordinal data. B) Parametric tests are used for ordinal and nominal data, whereas nonparametric tests are used for interval and ratio data. C) Parametric tests are used for ordinal or interval data, whereas nonparametric tests are used for nominal data only. D) There is no distinction; both types of tests are used to analyze data on any scale of measurement.
A
A Pearson r statistic would be the proper statistic to use to test the relationship between A) height and birth order (1st born, 2nd born, etc.) B) height and weight C) retirement status (yes or no) and blood pressure D) retirement status (yes or no) and death penalty view (pro vs. con)
B
The correlation coefficient is used to measure the ________ and ________ of the linear relationship between two factors. A) mean; variance B) strength; direction C) significance; effect size D) date; time
B
The correlation coefficient measures the extent to which changes in one factor are _______ in a second factor. A) causing variability B) related to changes C) causing changes D) all of the above
B
The correlation coefficient ranges from -1.0 to +1.0, with values closer to ±1.0 indicating A) that the correlation is due to outliers B) a more positive relationship between two factors C) that two factors are less likely to be related D) a stronger relationship between two factors
D
