Question

what is the purpose of a regression line?

to connect all the points in a scatterplot
to show the general tendency of the points in a scatterplot
to provide a scale for the \\(x\\)-coordinates of the points in a scatterplot
to provide a scale for the \\(y\\)-coordinates of the points in a scatterplot

Explanation:

Analyze the definition of a regression line

A regression line (or line of best fit) is a straight line drawn through the center of a group of data points on a scatterplot to show how the variables are generally related.

Evaluate the given options

• "to connect all the points in a scatterplot": Incorrect, as a straight line rarely passes through every single scattered data point.
• "to show the general tendency of the points in a scatterplot": Correct, because it models the overall trend or pattern of the bivariate data.
• "to provide a scale for the x-coordinates...": Incorrect, scales are provided by the axes.
• "to provide a scale for the y-coordinates...": Incorrect, scales are provided by the axes.

Answer:

• to connect all the points in a scatterplot
• to show the general tendency of the points in a scatterplot (Correct answer)
• to provide a scale for the x-coordinates of the points in a scatterplot
• to provide a scale for the y-coordinates of the points in a scatterplot