5. The following data show salaries y and the grade point averages z for students who obtained a bachelor's degree in Economics. The estimated regression equation for these data is 1790.5+581.1.x. [Show steps when applicable] 2.6 3.4 3.6 3.2 3.5 2.9 3 3300 3600 4000 3500 3900 3600 a. When no information for GPA is given, the estimate of salary is = b. In the given data how much is the estimated error when the GPA is 2.9? c. If Jim has a perfect GPA (4.0), how much salary can he expect? d. If Jack increases his GPA by 1.0, how much more salary can he expect?