Suppose 8 of 20 students in a grade-school class develop influenza, whereas 20% of grade-school students nationwide develop influenza. LO USE SALT (a) Is there evidence of an excessive number of cases in the class? That is, what is the probability of obtaining at least 8 cases in this class if the nationwide rate holds true? (Round your answer to four decimal places.) (b) What is the expected number of students in the class who will develop influenza