Old Navy is considering opening a new store in the college town of Falls Creek, but realizes the marketing department needs to know something about the demographics. The nearby university has 15000 students. The Gap conducts a survey by selecting a random sample of 400 students with 100 being older than 21.They want to use the sample understand the demographics of the nearby university studetns.
a) The percentage of students in the population who are older than 21 will be around ________, give or take ______.
b) Find the expected value and the standard error for the percentage of students in the population who are 21 or younger.
c) Find the estimated chance in the population that between 37% and 43% of the students will be older than 21.
d) Find the expected value with a 95% confidence interval for the number of students in the population who are older than 21?