A computer program, MicroLab, deals with finding the best fit curve, or allowing for linear regression of the first, second, and third orders, of a given set of data (particularly modeling nonlinear data). I am trying to stimulate this analysis on a graphing calculator (i.e., TI-83 Plus and TI-84 Silver Edition) used in some statistics courses. However, I am confused about how to define the second and third orders before executing the command to find the regression line’s equation/correlation. For the second (quadratic) order curve fit choice, do I plot the original y-values versus the square of the x-values? Based on the same concept, do I plot the original y-values versus x-values cubed for the third (cubic) order curve fit choice? Thank you for your time.