Scatterplots and Trendlines

Front

What is a scatterplot?

Back

A scatterplot is a graph that shows the relationship between two quantitative variables by displaying data points on a two-dimensional grid.

Front

What does a trendline represent in a scatterplot?

Back

A trendline, or line of best fit, represents the general direction or pattern of the data points in a scatterplot.

Front

How can you determine if a relation is a function from a scatterplot?

Back

A relation is a function if each input (x-value) corresponds to exactly one output (y-value). This can be visually checked using the vertical line test.

Front

What is the purpose of the line of best fit?

Back

The line of best fit is used to make predictions about the data and to summarize the relationship between the variables.

Front

How do you interpret the slope of a trendline?

Back

The slope of a trendline indicates the rate of change between the two variables; a positive slope means that as one variable increases, the other also increases.

Front

What does it mean if a trendline has a negative slope?

Back

A negative slope indicates that as one variable increases, the other variable decreases.

Front

What is the difference between a line of best fit and a line that passes through two points?

Back

A line of best fit minimizes the distance from all data points, while a line through two points only connects those two points and may not represent the overall trend.

Front

How can you use a trendline to make predictions?

Back

You can use the trendline to estimate the value of one variable based on the value of the other variable by finding the corresponding point on the line.

Front

What does it mean if a scatterplot shows no clear trend?

Back

If a scatterplot shows no clear trend, it suggests that there is no significant relationship between the two variables.

Front

What is an outlier in a scatterplot?

Back

An outlier is a data point that lies significantly outside the general pattern of the data, which can affect the trendline.