Statistics and Correlation Quiz

What does Pearson's correlation coefficient (r) measure?

• The difference between two variables

• The average of two variables

• The strength of a linear relationship between two variables

• The sum of two variables

What is the range of the correlation coefficient (r)?

• 0 to 100

• -1 to +1

• 0 to 1

• -∞ to +∞

What does a correlation coefficient of 0 indicate?

• Perfect positive correlation

• No linear correlation

• Perfect negative correlation

• Strong correlation

Which of the following is a limitation of Pearson's correlation?

• It only measures linear relationships

• It can only be used with categorical data

• It is not affected by outliers

• It requires a large sample size

What is the primary focus of rank correlation?

• Monotonic relationships

• Linear relationships

• Causal relationships

• Non-linear relationships

What does Spearman's rank correlation coefficient (ρ or rs) assess?

• Variability in data

• Causal relationships

• Monotonic relationships based on ranks

• Linear relationships based on raw data

What is the null hypothesis (H₀)?

• The observed result in a sample

• The probability of observing a test statistic

• A statement that contradicts the null hypothesis

• A statement assumed to be true initially

What does a p-value indicate?

• The strength of the correlation

• The significance level of the test

• The probability of observing a test statistic as extreme as the one calculated

• The sample size used in the test

What is the coefficient of determination (R²)?

• The proportion of variance in the dependent variable explained by the independent variable

• The average of the dependent variable

• The total number of observations

• The difference between predicted and actual values

What does R² = 1 signify?

• The model explains no variability in the dependent variable

• The model is not applicable

• The model explains all variability in the dependent variable

• The model has a weak fit