Correlation and Regression Quiz

What does the correlation coefficient 'r' represent?

• The sum of the y-values

• The average of the x-values

• The strength and direction of a linear relationship

• The slope of the regression line

What is the range of the correlation coefficient?

• 0 to 1

• -∞ to +∞

• 0 to 100

• -1 to 1

What type of correlation exists when 'r' is close to -1?

• No correlation

• Strong negative correlation

• Weak positive correlation

• Strong positive correlation

What is the first step in calculating the correlation coefficient?

• Find the sum of the y-values

• Find the sum of the x-values

• Multiply each x-value by its corresponding y-value

• Square each y-value

What does a scatter plot help to determine?

• The mode of the data

• The median of the data

• The mean of the data

• The correlation between two variables

What is the equation of a regression line?

• y = mx^2 + b

• y = ax^2 + bx + c

• y = mx + b

• y = m + b

What does the coefficient of determination (r²) represent?

• The total variation in the data

• The ratio of explained variation to total variation

• The slope of the regression line

• The average of the residuals

What is a residual?

• The correlation coefficient

• The average of y-values

• The sum of all x-values

• The difference between observed and predicted y-values

What is the purpose of hypothesis testing for the correlation coefficient?

• To find the mean of the data

• To determine if the correlation is significant

• To calculate the slope of the regression line

• To find the mode of the data

What does a negative linear correlation indicate?

• The correlation is strong

• As x increases, y tends to increase

• There is no correlation

• As x increases, y tends to decrease