.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 of the university in Falls Creek that has 15000 students. The Gap conducts a survey by selecting a random sample of 400 students with 100 being older than 21. The standard deviation is 1. They want to use the sample to understand the demographics of the population of university students.

a)Use a 95% confidence level to calculate: 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 using a 95% confidence level.

c)They decide to collect the sample by standing at the local Wal-Mart and surveying the first 400 shoppers on the morning of July 4^th. What might be some issues with this sample methodology?

Normal Distributions

d)Find the estimated chance in the population that between 37% and 43% of the students will be older than 21. ( HINT: Remember you are in the inference world now)