A particular fast food restaurant is situated near a University. 40% of customers are students. Students prefer the spicier items. For example, a student customer will ask for extra hot sauce 75% of time whereas a non-student will ask for extra hot sauce only 30% of time. While waiting in line you observe a customer ask for extra hot sauce. Determine the probability that this customer isn't a student? The manager claims that about half the customers ask for extra hot sauce. Do you agree?