courses/78593/quizzes/401119/take Question 8 1 pts On a multiple choice test with 17 questions, each question has four possible answers, one of which is correct. For students who guess at all answers, find the mean for the number of correct answers. 8.5 questions 5.7 questions 12.8 questions 4.3 questions D Question 9 1 pt Find the critical value za/2 that corresponds to a 91% confidence level. 1,70 1,645 O 1.75 O 1,34