The Texas Instruments TI-84 series of graphing calculators provides built-in functionality for determining the equation of the line of best fit for bivariate data. This line, often referred to as the least squares regression line, minimizes the sum of the squares of the vertical distances between the observed data points and the line itself. For example, a student could input sets of x and y values representing study hours and exam scores, respectively. The calculator then computes the slope and y-intercept of the line that best represents the relationship between these two variables.
This capability is important for statistical analysis and data interpretation, offering a quick and accessible method for modeling linear relationships. Prior to the widespread availability of such calculators, these calculations required manual computation or specialized statistical software, making the process more time-consuming and complex. The calculator streamlines this process, allowing users to quickly assess the strength and direction of a linear association.