Answer to Question #207507 in Statistics and Probability for Fdukes20

Question

(a) The administration of an inner-city college has generally assumed that the average age of a student is no more than 20 years. The standard deviation of the age of students is known to be 3.6 from previous data. However, lately the students have appeared to be older than before, and some administrators say that the average age could be higher than 20 years. You collect a random age sample of 50 students and calculate a mean of 20.76. At the 90% level of confidence, can you conclude that the average age of students has indeed increased?