Statistics professor wants to ?nd out the average GPA (grade point average) for all students at UMKC. He uses all students enrolled in his statistics class as a sample and collects information on their GPAs to ?nd the average GPA.
(a) Identify the (statistical) population and (statistical) sample.
(b) Is this a random sample or nonrandom sample?
(c) What kind of sample is it? In other words, is it a simple random sample, a convenient sample, or a judgement sample?
Suppose another statistics professor at UMKC obtains a list of all students enrolled at UMKC from the registrar's o?ce and then selects 150 students at random from this list using a statistical software package such as Minitab. Then she collects information on their GPA also through the database of registrar's o?ce and ?nds another average GPA.
(d) Is this a random sample or nonrandom sample?
(e) What kind of sample is it? In other words, is it a simple random sample, a convenient sample, or a judgement sample? (Read the material on the back)
(f) Which of the average GPA, the one estimated by him or by her, is more representative to the population's GPA? Explains