A Study Investigated the Use of Social Media by Freshman

Multiple Choice

A study investigated the use of social media by freshman. One question asked if the person answering ever stayed up late to chat with friends and ended up sleep deprived. It was thought that at least 80% of all people of freshman age would stay up late. If the study sampled 400 students, which of the following statements is true?

A) The number of students in the sample who stay up late follows a binomial distribution with  = 320 and variance ² = 64.
B) The number of students in the sample who stay up late can be approximated by a Normal distribution with mean  = 320 and variance ² = 64.
C) The number of students in the sample who stay up late can be approximated by a Normal distribution with mean  = 320 and standard deviation  = 8.
D) All of the answer options are correct.