#1
Which of the following measures of central tendency is most affected by outliers?
#2
Which type of graph is most appropriate for visualizing the relationship between two quantitative variables?
Bar chart
Line graph
Scatter plot
Histogram
#3
In a normal distribution, what percentage of data falls within one standard deviation of the mean?
#4
Which graphical representation is used to display the distribution of data and its quartiles?
Histogram
Box plot
Scatter plot
Line graph
#5
What is the primary purpose of a histogram?
To show correlations between two variables
To display the distribution of a single quantitative variable
To compare means across several groups
To illustrate changes over time
#6
What does the standard deviation measure in a dataset?
Central tendency
Data dispersion
Data skewness
Data kurtosis
#7
Which correlation coefficient value indicates the strongest relationship between two variables?
#8
What does a p-value less than 0.05 typically indicate in hypothesis testing?
The null hypothesis cannot be rejected
The null hypothesis can be rejected
The data is not normally distributed
The sample size is too large
#9
What is the main difference between T-tests and Z-tests?
T-tests are used for large sample sizes, while Z-tests are used for small sample sizes
Z-tests are used for large sample sizes, while T-tests are used for small sample sizes
T-tests are used for data without variance, while Z-tests are used for data with variance
Z-tests require knowing the population variance, while T-tests do not
#10
Which measure is used to assess the skewness of data distribution?
Kurtosis
Standard deviation
Skewness
Variance
#11
In time series analysis, what does the term 'seasonality' refer to?
Trends that repeat at specific regular intervals within a year
Long-term trends in data over several years
Irregular fluctuations that do not follow a pattern
Cyclical trends that take more than a year to complete
#12
What statistical test is used to compare the means of two related samples?
Independent samples T-test
ANOVA
Paired T-test
Chi-square test
#13
In a regression analysis, what does an R-squared value of 1 indicate?
No correlation between the dependent and independent variables
Perfect negative linear relationship
Perfect positive linear relationship
Data is randomly dispersed
#14
What is the purpose of using ANOVA (Analysis of Variance) in statistical analysis?
To compare means of two groups
To compare variances of two groups
To compare means of more than two groups
To compare variances of more than two groups
#15
Which statistical test is appropriate for comparing the means of more than two independent groups?
Paired T-test
One-way ANOVA
Chi-square test
Pearson correlation
#16
Which test is used to determine if there are significant differences between the distributions of two independent samples?
ANOVA
T-test
Chi-square test
Mann-Whitney U test
#17
What does the coefficient of determination (R^2) indicate in linear regression analysis?
The proportion of the variance in the dependent variable that is predictable from the independent variable(s)
The strength of the correlation between the dependent and independent variables
The average distance of the data points from the fitted regression line
The total variance explained by the model
#18
What is the purpose of performing a Box-Cox transformation in data preprocessing?
To normalize the residuals in regression analysis
To convert categorical data into numerical data
To handle missing data
To create a scatter plot
#19
Which of the following is a non-parametric statistical test?
Z-test
T-test
Kruskal-Wallis H test
ANOVA