Given below are seven observations collected in a regression study on two variables, x (independent variable) and y (dependent variable). x y 2 12 3 9 6 8 7 7 8 6 7 5 9 2 a. develop the least squares estimated regression equation. b. at a 95% confidence, perform a t test and determine whether or not the slope is significantly different from zero. c. compute the coefficient of determination and explain what it means.