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 plane.

Front

What does a line of best fit represent in a scatterplot?

Back

A line of best fit represents the trend of the data points in a scatterplot, indicating the general direction of the relationship between the variables.

Front

How do you determine the line of best fit?

Back

The line of best fit is determined by minimizing the distance between the line and all the data points, often using a method called least squares.

Front

What does a positive correlation in a scatterplot indicate?

Back

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

Front

What does a negative correlation in a scatterplot indicate?

Back

A negative correlation indicates that as one variable increases, the other variable tends to decrease.

Front

What does no correlation mean in a scatterplot?

Back

No correlation means there is no apparent relationship between the two variables; the data points do not show any trend.

Front

What is the purpose of a trendline in a scatterplot?

Back

The purpose of a trendline is to summarize the data and make predictions about future values based on the observed relationship.

Front

How can you use a trendline to make predictions?

Back

You can use a trendline to predict values by extending the line beyond the existing data points and finding the corresponding value on the other axis.

Front

What is the formula for the slope of a line?

Back

The formula for the slope (m) of a line is m = (y2 - y1) / (x2 - x1), where (x1, y1) and (x2, y2) are two points on the line.

Front

What is the y-intercept of a line?

Back

The y-intercept is the point where the line crosses the y-axis, indicating the value of y when x is zero.