Refer to Exercise A.9. Suppose the professor enters the names of all students enrolled in his class on a computer. He then selects a sample of 20 students at random using a statistical software package such as Minitab.
a. Is this sample a random or a nonrandom sample? Explain.
b. What kind of sample is it? In other words, is it a simple random sample, a systematic sample, a stratified sample, a cluster sample, a convenience sample, a judgment sample, or a quota sample? Explain.
c. Do you think any systematic error will be made in this case? Explain.