Algebra 1A - Module 4B Review

Front

What is a residual plot?

Back

A residual plot is a graph that shows the residuals on the vertical axis and the independent variable on the horizontal axis. It helps to assess the fit of a regression model.

Front

When is a linear regression model appropriate?

Back

A linear regression model is appropriate when the residual plot shows no patterns, indicating that the relationship between the variables is linear.

Front

What does a correlation of 0 indicate?

Back

A correlation of 0 indicates no correlation between the two variables, meaning changes in one variable do not predict changes in the other.

Front

What does a strong negative correlation (e.g., r = -0.87) imply?

Back

A strong negative correlation implies that as one variable increases, the other variable tends to decrease significantly.

Front

What does a weak positive correlation (e.g., r = 0.3) imply?

Back

A weak positive correlation implies that there is a slight tendency for one variable to increase as the other variable increases, but the relationship is not strong.

Front

How do you calculate expected earnings based on hours worked?

Back

Expected earnings can be calculated by multiplying the hourly wage by the number of hours worked.

Front

What is the formula for correlation coefficient (r)?

Back

The correlation coefficient (r) is calculated using the formula: r = (nΣxy - ΣxΣy) / sqrt[(nΣx^2 - (Σx)^2)(nΣy^2 - (Σy)^2)], where n is the number of pairs.

Front

What does a positive correlation indicate?

Back

A positive correlation indicates that as one variable increases, the other variable also tends to increase.

Front

What is the significance of a correlation coefficient close to 1?

Back

A correlation coefficient close to 1 indicates a strong positive linear relationship between the two variables.

Front

What is the significance of a correlation coefficient close to -1?

Back

A correlation coefficient close to -1 indicates a strong negative linear relationship between the two variables.