1.What is least squares regression analysis? What is meant by the total explained, and unexplained variation in the dependent variable. Why is it important to conduct a significance test of the estimated coefficients? Given the attached t-table what are the t-values required for a variable to be significant at the p0.01 and p0.05 and p0.10 levels if the degrees of freedom are 3,5,10,16,23,30,60 and infinity.