ture.com/courses/78593/quizzes/secured#lockdown Question ZU 5 pts Do one of the following, as appropriate: (a) Find the critical value za/2, (b) find the critical value ta/2. 99%; n = 17; a is unknown; population appears to be normally distributed. O Zo/2 = 2.583 O to/2 = 2.898 O to/2 = 2.921 O Zo/2 = 2.567 D Question 21 5 pts Find the value of the linear correlation coefficient r. The paired data below consist of the costs of advertising (in thousands of dollars) and the number of products sold (in thousands). Cost 9 2 3 4 2 5 9 10 Number 85 52 55 68 67 86 83 73 O 0.235 O 0.246 O -0.071 0 0.708