Joe thinks that no more than 20% of students in his statistics class will get an A in the final examination. To prove his claim, he takes a random sample of 35 students and finds to his suprise that 30% of his students got an A. At a .01 percent level of significance can we reject Joe's view? I do not want the answer to this question, I would just like to know what formula to use, and why. Thank you so much I really appreciate it.