First Term Quiz Mathematics 12 Reviewer

Which of the following represents a linear equation?

• y = 2x² + 3

• y = 5x + 7

• y = (1/4)x + 8

• y = sqrt(x) + 2

In the context of linear regression, what does the slope of the regression line represent?

• The value of y when x = 0

• The average change in y  for each unit increase in x

• The total variation in  y

• The correlation between  x and  y

Which statistical measure indicates the strength and direction of a linear relationship between two variables?

• Coefficient of determination

• Linear correlation coefficient

• Slope of the regression line

• Residuals

What is the range of values for the linear correlation coefficient r ?

• [0, 1]

• [-1, 1]

• [0, infinity)

• (-infinity, infinity)

The coefficient of determination R² measures what?

• The slope of the regression line

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

• The correlation between the dependent and independent variables

• The total variance of the dependent variable

If a linear regression model has an R² value of 0.85, what can be inferred?

• 15% of the variation in y is explained by x.

• 85% of the variation in y is explained by x.

• There is no linear relationship between x and y.

• The relationship is perfectly linear.

What does a residual in a regression analysis represent?

• The predicted value of the dependent variable

• The actual value of the dependent variable

• The difference between the actual and predicted values of the dependent variable

• The variance of the dependent variable

In a one-way ANOVA, what does the null hypothesis state?

• All group means are equal

• At least one group mean is different

• The data is normally distributed

• There is no correlation among groups

What is the purpose of Tukey’s HSD test?

• To assess the strength of correlation

• To compare means among groups after a one-way ANOVA

• To predict future values of a variable

• To calculate residuals

If the p-value from a one-way ANOVA is less than 0.05, what conclusion can be drawn?

• There is no significant difference among group means.

• At least one group mean is significantly different.

• All groups have the same variance.

• The regression model is not significant.