19. when cells or rows are inserted or deleted in an excel worksheet, how are cell references affected by the insertion or deletion? a) cell references are not affected. b) the user must insert new cell references c) the user is prompted to enter new cell references d) cell references are automatically adjusted

Least square fit to polynomial write a function leastsquarefit3pol that solves a linear system of equations to find a least squares fit of a third order polynomial to an experimental data set given as two row arrays. the function leastsquarefit3pol must explicitly solve a set of linear equations and cannot use polyfit. there should be no restriction on the size of the problem that can be solved.