I need help with question #2 ONLY

Directions: Answer all questions, show all work on the provided answer pages. Questions 1 & 2 deal with the Central Limit Theorem. Questions 3 & 4 are confidence interval questions. Please note that Hypothesis Testing will be tested on the final exam. 1. The amount of time of an iPhone battery lasts before it fails is normally distributed with mean 5.2 years and standard deviation of 1.3 years. Apple randomly selects 100 iPhones for testing. Is it a likely event that the mean lifetime of the iPhone's batteries will be greater than 5.7 years? Show mathematical proof for your answer. 2. The mean grade on a statistics examination was 70 and the standard deviation was 7. The instructor gives the exam to one of his classes this semester. However, the instructor was absent, and a substitute administered the exam. The class contains 32 students. The mean score for the 32 students exceeded 75. Is this odd? What should the instructor conclude & why? 3. Mike's housemate Ally is trying to convince Mike to get a piercing. Mike is very sensitive to popular opinion, and will only get one if "everyone else is doing it". Mike will get the piercing if Ally can show that more than 50% of students at Mike's college have one. Ally wastes no time in taking a random sample of 120 people from Mike's campus. Her sample of 120 revealed 72 people who admitted to