professor river has developed a new method for teaching high school students to drive. he claims that 75% of students would passed his state's "Safe Driver" test within 4 weeks if they took his course. We are interested in whether the percentage is actually lower than what he claims. A random sample of 90 high school students are enrolled in his course. After 4 weeks, 72% of the 90 students passed the test. The null and alternative hypothesis are: