Multiple Choice Questions from textbook

Twenty-one cats were given 300g of tuna each. The time in seconds was measured until they had eaten all of the tuna: 16, 18, 18, 22, 22, 23, 23, 24, 26, 29, 32, 34, 34, 36, 36, 42, 43, 46, 46, 49, 57 Compute the median. A. 32 secs B. 22.5 secs C. 42.5 secs D. 20 secs

A. 32 secs

Rank the score of 5 in the following set of scores: 9, 3, 5, 10, 8, 5, 9, 7, 3, 4 A. 4.5 B. 4 C. 3 D. 6

A. 4.5

The covariance is: A. All of these B. A measure of the strength of relationship between two variables. C. Dependent on the units of measurement of the variables D. An unstandardized version of the correlation coefficient.

A. All of these

R2 is known as the: A. Coefficient of determination B. Multiple correlation coefficient C. Partial correlation coefficient D. Semi-partial correlation coefficient

A. Coefficient of determination

If we use the mean as a model, what does the variance represent? A. The average error between the model and the observed data. B. The total error between the model and the observed data. C. The squared total error between the model and the observed data. D. The square-root average error between the model and the observed data.

A. The average error between the model and the observed data.

Differences between group means can be characterized as a regression (linear) model if: A. The experimental groups are represented by a binary variable (i.e. code to 0 and 1) B. The outcome variable is categorical C. The groups have equal sample sizes D. Differences between group means cannot be characterized as a linear model, they mist be analyzed with an independent t-test.

A. The experimental groups are represented by a binary variable (i.e. code to 0 and 1)

Which of these statements describes a Bonferroni correction? A. You apply a criterion for significance base on the usual criterion for significance (.05) divided by the number of tests performed. B. You divided the F-ration by the number of tests preformed C. The degrees of freedom are corrected to make the F-ratio less significant D. The error in the model is adjusted for the number of tests preformed

A. You apply a criterion for significance base on the usual criterion for significance (.05) divided by the number of tests performed.

Given a test is normally distributed with a mean of 30 and a standard deviation of 6: What is the probability that a single score drawn at random will be greater than 34? A. 0.0228 B. 0.2524 C. 0.1826

B. 0.2524

Out of the following options, which type of bar chart would we produce to look at the mean ratings of 'taste' and 'value for money' for two new varieties of Sauvignon Blanc wine? A. Clustered bar chart B. All of the options are possible C. Stacked bar chart D. 3D bar Chart

B. All of the options are possible

A researcher measured people's physiological reactions to horror films. He split the data into two groups: males and females. The resulting data were normally distributed and men and women had equal variances. What test should be used to analyse the data? A. Dependent B. Independent t-test C. Mann-Whitney test D. Wilcoxon signed-rank test

B. Independent t-test

Which of the following statements about outliers is not true? A. Outliers are values very different from the rest of the data B. Influential cases will always show up as outliers C. Outliers have an effect on the mean D. Outliers have an effect on regression parameters

B. Influential cases will always show up as outliers

A researcher was interested in stress levels of lecturers during lectures. She took the same group of 8 lecturers and measured their anxiety (out of 15) during a normal lecture and again in a lecture in which she had paid students to be disruptive and misbehave. What test is best used to compare the mean level of anxiety in the two lectures? A. Independent sample t-test B. Paired-samples t-test C. One-way independent ANOVA D. Mann-Whitney test

B. Paired-samples t-test

Variation due to some genuine effect is known as: A. Unsystematic variation B. Systematic variation C. Homogeneous variance D. Residual variance

B. Systematic variation

Which of the following does a box-whisker plot not display? A. The mean B. The median C. Outliers D. The lower quartile

B. The median

If we were to pull all possible samples from a population, calculate the mean for every sample, and construct a graph of the shape of the distribution based on all of the means, what would we have? A. The population distribution of the mean B. The sampling distribution of the mean C. The bootstrap distribution of the mean D. The standard error of the mean

B. The sampling distribution of the mean

Levene's test tests whether: A. Data are normally distributed. B. The variances in different groups are equal C. The assumption of sphericity has been met. D. Groups means differ.

B. The variances in different groups are equal

The owner of the large chain of coffee shops called 'MoonBucks' decided to calculate how much revenue was gained from lattes each month in a nationwide sample of 2445 cafés. To measure the variance of revenue gained from lattes, he computes SS = 351,936 for this sample. What are the degrees of freedom for variance? Compute the variance. Compute the standard deviation. A. 144 B. 12 C. 2444

C. 2444

How much variance has been explained by a correlation of .9? A. 18% B. 9% C. 81% D. None of these

C. 81%

Which of the following is not a type of post hoc test? A. Games-Howell B. Bonferroni C. Cramer D. REGWQ

C. Cramer

If we calculated an effect size and found it was r = .42 which expression would best describe the size of effect? A. Small B. Small to Medium C. Medium to Large D. Large

C. Medium to Large

Which of the following statistical tests allows causal inferences to be made? A. Analysis of variance B. Regression C. None of these, it's the design of the research that determines whether casual inferences can be made. D. t-test

C. None of these, it's the design of the research that determines whether casual inferences can be made.

Which of the following is the least affected by outliers? A. the range B. the mean C. the median D. the standard deviation

C. the median

If Pearson's correlation coefficient between stress level and workload is .8, how much variance in stress level is not accounted for by workload? A. 20% B. 2% C. 8% D. 36%

D. 36%

A researcher measured people's physiological reactions while watching a horror film and compared them to when watching a comedy film, and a documentary about wildlife. Different people viewed each type of film. The resulting data were normally distributed and the variances across groups were similar. What test should be used to analyse the data? A. Repeated-measures analysis of variance B. Kruskal-Wallis test C. Friedman's ANOVA D. Independent analysis of variance

D. Independent analysis of variance

What does the error bar on an error bar chart represent? A. The confidence interval around the mean B. The standard error of the mean C. The standard deviation of the mean D. It can represent any of these

D. It can represent any of these

An experimenter measured 30 children's IQ. He then rank-ordered the children and assigned them a score from 30 (most intelligent) to 1 (least intelligent) to create a new variable. Does this new variable consist of: A. Nominal Data B. Interval Data C. Ratio Data D. Ordinal Data

D. Ordinal Data

Which of the following is not a transformation that can be used to correct skewed data? A. Log transformation B. Squareroot transformation C. Reciprocal transformation D. Tangent transformation

D. Tangent transformation

When variances across independent groups are unequal, which of the following is not an appropriate course of action? A. Use Games-Howell post hoc tests B. Use Kruskal-Wallis test C. Use Welch's F-ratio D. Use Friedman's ANOVA

D. Use Friedman's ANOVA

What is the relationship between the sum of squared errors (SS), the sample size (n) and the variance (s2)? A. SS= s2/(n-1) B. s2= SS(n-1) C. n= (s2/SS) - 1 D. s2= SS/(n-1)

D. s2= SS/(n-1)

The t-test tests for: A. Difference between means B. Whether a correlation is significant C. Whether a regression coefficient is equal to zero D. All of these

D. All of these

Out of the following options, which type of bar chart would we produce to look at the mean ratings of two new varieties of Sauvignon Blanc (wine)? A. Clustered bar chart B. Stacked Bar Chart C. Simple 3D bar chart D. Simple bar Chart

D. Simple bar Chart

Approximately what percentage of people would have scores lower than an individual with a z-score of 1.65 in a normally distributed sample? A. 95% B. 98% C. It is not possible to calculate this unless the mean and standard deviation are given D. 1%

A. 95%

Which of the following are assumptions underlying the use of parametric tests (based on the normal distribution)? A. All of the options are true B. Some feature of the data should be normally distributed C. The samples being tested should have approximately equal variances D. The data should be at least interval level

A. All of the options are true

The degree to which a statistical model represents the data collected is known as the: A. Fit B. Homogeneity C. Reliability D. Validity

A. Fit

A correlation of .7 was found between time spent studying and percentage on an exam. What is the proportion of variance in exam scores that can be explained by time spent studying? A. .70 B. .49 C. .30 D. .7

B. .49