2D-3A Review

Front

What is the population in a survey?

Back

The population is the entire group of individuals or instances about whom we hope to learn, such as Californians in the context of a survey about the governor.

Front

What is a residual in regression analysis?

Back

A residual is the difference between the observed value and the predicted value from a regression model.

Front

What does it mean to take a census in research?

Back

Taking a census means collecting data from every member of the population.

Front

What indicates a good model in a residual plot?

Back

A good model is indicated by a residual plot that shows no clear pattern, suggesting that the model adequately captures the relationship in the data.

Front

How do you calculate the percentage of variation explained by a correlation coefficient?

Back

The percentage of variation explained is calculated by squaring the correlation coefficient (r) and multiplying by 100. For r=0.8, it is 64%.

Front

What is the purpose of a least-squares regression line?

Back

The least-squares regression line is used to model the relationship between an explanatory variable and a response variable by minimizing the sum of the squares of the residuals.

Front

What does a correlation coefficient of r=0.8 indicate?

Back

A correlation coefficient of r=0.8 indicates a strong positive linear relationship between the two variables.

Front

What is the role of an explanatory variable in a regression model?

Back

The explanatory variable is the independent variable that is used to predict the value of the response variable.

Front

What is a scatterplot?

Back

A scatterplot is a graphical representation of the relationship between two quantitative variables, showing individual data points.

Front

What does it mean if a residual plot shows a clear pattern?

Back

If a residual plot shows a clear pattern, it indicates that the model may not be appropriate for the data, suggesting that there are other factors influencing the response variable.