Psych 311 Exam 4 Study Guide

Draw a scatterplot showing a positive correlation between age and # of emotion-focused goals.

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If r = .25, then the coefficient of determination is .=_________06.

.06 (.0625 without rounding)

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

A) 0.04

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? 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

A) The more a person works, the more coffee he or she tends to drink

A correlation of r = .38 in a sample of 30 participants is statistically significant for a two-tailed test at a .05 level of significance. A) True B) False

A) True

The coefficient of determination is mathematically equivalent to eta-squared. A) True B) False

A) True

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. A) Graph A; Graph B B) Graph B; Graph A C) Graph A; Graph A D) Graph B; Graph B

B) Graph B; Graph A

Suppose a correlation is computed in each of two samples. If the value of SSxy is the same in each sample, and squareroot of SSxSSy is larger in Sample 1, then in which sample will the value of the correlation coefficient be larger? 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

B) Sample 2

The correlation coefficient ranges from -1.0 to +1.0., with values closer to +/-1.0 indicating 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

B) a stronger relationship between two factors

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

B) vary independently

The correlation coefficient ranges between _______ and _______. A) 0; +1 B) -1; 0 C) -1; +1 D) -infinity; +infinity

C) -1; +1

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? A) 0.32 B) 0.34 C) 0.60 D) almost a zero correlation

C) 0.60

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? A) 0.002 B) 0.02 C) 0.66 D) 0.69

C) 0.66

A statistical procedure used to describe the strength and direction of the linear relationship between two factors is called A) effect size B) power C) a correlation D) coincidence

C) a correlation

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

C) r = -0.90

The numerator of the correlation coefficient measures the extend to which two variables A) vary together B) vary independently C) Covary D) both A and C

D) both A and C

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

D) strength; direction

The sign (+ or -) of a correlation coefficient indicates the ________ of a relationship between two factors.

direction

The Spearman correlation coefficient is used to measure the correlation between two variables that are measured on a(n) ________ scale.

ordinal.

The _______ correlation coefficient is used to measure the correlation between two dichotomous variables.

phi

The formula for the Spearman correlation coefficient was derived from the formula for ________.

the Pearson correlation coefficient (or just "Pearson r")