Unit 2 - Scatterplots

Scatterplot

A graphical representation of data points on a Cartesian coordinate system where each point represents the values of two different variables. It helps in identifying trends, correlations, or patterns in the data.

Explanatory variable

The variable that is manipulated or controlled in an experiment to observe its effect on another variable.

Response variable

The variable that measures the effect of the explanatory variable in an experiment, often what is being tested or measured.

Direction

refers to the trend of a scatterplot, indicating whether the relationship between the variables is positive, negative, or no correlation.

Positive association

describes a relationship where, as one variable increases, the other variable also increases, indicating a direct correlation.

Negative association

describes a relationship where, as one variable increases, the other variable decreases, indicating an inverse correlation.

No association

describes a relationship in which there is no discernible trend between the variables, indicating that changes in one variable do not affect the other.

Form

of association in scatterplots that indicated a linear or curved correlation between two variables.

Linear

indicates a straight-line relationship (form) between two variables in a scatterplot.

Curved

indicates a non-linear relationship (form) between two variables in a scatterplot, where the data points follow a curved path.

Clusters

groups of points in a scatterplot that are close to each other, suggesting a relationship or pattern among the variables.

Strength

refers to the degree of association or correlation between two variables in a scatterplot, indicating how closely the data points align with a trend line.

Strong relationship

exists when data points in a scatterplot closely follow a clear trend, either positively or negatively, indicating a high degree of correlation.

Weak relationship

indicates a low degree of association between two variables in a scatterplot, where data points are widely dispersed and do not follow a clear trend.

Outliers

are data points in a scatterplot that fall far outside the overall pattern of the other points, potentially skewing the interpretation of the relationship between the variables.

State

____ the question: 4 step process

Plan

____ to describe how you will answer the question: 4 step process

Do

__ any calculations, make a graph, or whatever

Conclude

__ by writing a conclusion in the context of the problem

Point of high leverage

a data point that significantly influences the slope of the regression line due to its extreme position. It’s x value is far from the mean of x, while the y value is close to the line of best fit.