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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.

Ihave been given the number of guns per 100, and the total firearm-related deaths per 100,000. i have to find the actual number of guns per country and actual number of gun-related deaths. if somebody could show me how to do 1 question, i can finish the rest, i am just confused. tia