What is a line of best fit?

The line of best fit is defined as a straight line drawn through a scatter plot that best represents the relationship between the variables plotted on the graph. This line is determined through statistical methods that minimize the distance between the data points and the line itself, typically using the least squares criterion. The purpose of the line of best fit is to summarize the data in a way that allows for easier interpretation and prediction of one variable based on the other.

In context, the other choices do not provide accurate descriptions of the line of best fit. A curve may represent certain trends effectively, but it deviates from the idea of a straight line which is specifically used in linear regression analysis to predict outcomes. A dashed line indicating uncertainty does not fulfill the role of depicting the central tendency or predictive value of the data, and a line connecting the highest and lowest points fails to capture the broader trend represented by multiple data points. Hence, the straight line that summarizes the overall tendency of the data is indeed the correct definition of a line of best fit.