The correct answer choices are marked in blue :
1.When a distribution is extremely skewed, the best measure of central tendency is typically the:
2.According to the central limit theorem, the shape of the distribution of sample means is always:
3.The standard deviation of the distribution of sample means is called:
4.Systematic measurement error represents:
5.What value is expected for the t statistic if the null hypothesis is true?
6.What happens to the t-distribution as sample size increases?
15.In a standard regression analysis, if the unstandardized regression coefficient is 2 and the standard
1.When a distribution is extremely skewed, the best measure of central tendency is typically the:
- mean
- median
- standard deviation
- standard error
2.According to the central limit theorem, the shape of the distribution of sample means is always:
- positively skewed
- uniform
- normal
- negatively skewed
3.The standard deviation of the distribution of sample means is called:
- percent error
- special error
- standard error
- likely error
4.Systematic measurement error represents:
- bias
- chance error
- outliers
- covariance
5.What value is expected for the t statistic if the null hypothesis is true?
- 1
- 0
- 2
- 1.96
6.What happens to the t-distribution as sample size increases?
- The distribution appears more and more like a normal distribution
- The distribution appears less and less like a normal distribution
- The distribution becomes uniform
- The distribution is unaffected
- N
- N + 1
- N - 1
- the square root of N
- the standard deviation of the distribution of sample means
- the pooled standard deviation
- the standard deviation of the distribution of sample mean differences
- the standard deviation of the sample means
9.How many subjects were included in an independent samples t-test if a researcher reports t(20) = 3.68
- 20
- 19
- 22
- 18
10.In a factorial ANOVA, a significant interaction effect indicates that:
- the influence of one IV is the same for each level of the other IV
- the influence of one IV is not the same for each level of the other IV
- the influence of one IV is different from the influence of the other IV
- the dependent variable differs depending on the level of an independent variable (IV)
11.In any factorial ANOVA, if FAxB is significant, then which of the following is true?
- FA is significant
- FB is significant
- Both FA and FB are significant
- None of the above
12. The General Linear Model assumes that the relationships between predictor variables (X’s) and the outcome variable (Y) are:
- Linear
- Additive
- Linear and additive
- None of the above
13.In null hypothesis significance testing, if the probability of a Type II error is .20 and alpha = .04, then what is power?
- .20
- .40
- .60
- .80
14. If the 68% confidence interval for the regression coefficient for predictor X does not contain zero, can you safely assume that the effect of X on an outcome variable Y will be significant with alpha = .05?
- No
15.In a standard regression analysis, if the unstandardized regression coefficient is 2 and the standard
error of the regression coefficient is 4 then what is the corresponding t-value?
- t = 0.25
- t = 0.50
- t = 0.75
- t = 1
16.Pearson’s product moment correlation coefficient (r) is used when X and Y are:
- Both nominal variables
- Both categorical variables
- Both dichotomous variables
- Both continuous variables
17. In a regression analysis, which distribution will have the largest standard deviation?
- the residuals
- the predicted scores on the outcome variable
- the standardized regression coefficients
- the observed scores on the outcome variable
18. In multiple regression analysis, the null hypothesis assumes that the unstandardized regression
coefficient, B, is zero. The standard error of the regression coefficient depends on:
- Sample size
- Sample size and the Sum of Squared Residuals
- Sample size, Sum of Squared Residuals, and the number of other predictor variables in the regression model
- Sample size, Sum of Squared Residuals, the number of other predictor variables in the regression model, and the p-value
19. Which of the following r-values indicates the strongest relationship between two variables?
- +.65
- -.89
- +.10
- -.10
20.What is the slope in the following regression equation? Y = 2.69X – 3.92
- 2.69
- -2.69
- 3.92
- -3.92
21. When we square the correlation coefficient to produce r2, the result is equal to the:
- proportion of variance in Y not accounted for by X
- proportion of variance in Y accounted for by X
- sum of squared residuals
- standard error
22.When testing for mediation, what significance test would you conduct to further strengthen your
argument for (or against) mediation?
- Tukey’s HSD
- Fisher’s Exact Test
- Sobel Test
- Bonferroni correction
23.Why it is preferable to conduct a one-way ANOVA to compare multiple sample means rather than a series of independent t-tests?
- More powerful error term
- Reduces the likelihood of Type I error
- Both a and b
- None of the above
24.The sphericity assumption assumes:
- homogeneity of variance
- homogeneity of covariance
- both a and b
- none of the above
25.Suppose a dependent t-test is conducted to compare scores in an experiment with a pre/post design (like the working memory training example). Suppose two experiments were conducted: A and B. In Experiment A the correlation between pre and post scores was high. In Experiment B the correlation between pre and post scores was low. Which Experiment would have a lower standard error, and why?
- Experiment A would have a lower standard error because the variance associated with subjects is more systematic.
- Experiment B would have a lower standard error because the variance associated with subjects is more systematic.
- Experiment A would have a lower standard error because the variance associated with subjects is less systematic.
- Experiment B would have a lower standard error because the variance associated with subjects is less systematic.
