In: Statistics and Probability
Which of the following scenarios contain nonbiased samples? Select all that apply. Select all that apply: To estimate the mean height of students at her school, Kelly collects data by selecting a random group of students within her classroom. Elizabeth wants to estimate the mean grade point average of students at her school. She collects data by recording the grade point average of every 25th student on the list of students after a randomly selected first student. Andrew wants to estimate the mean number of classes that students take at his university. He collects data from a randomly selected proportionate number of students from each grade level. To estimate the mean salary of professors at his university, Homer collects data by recording the salaries of all professors included in 12 randomly selected departments.
1) No, To estimate the mean height of students at her school, Kelly collects data by selecting a random group of students within her classroom. Here, she selects from her class only. Hence, this sample can not represent the whole school.
2. Yes, Elizabeth wants to estimate the mean grade point average of students at her school. She collects data by recording the grade point average of every 25th student on the list of students after a randomly selected first student. Here, the sample is selected randomly from whole school using systematic sampling.
3. Yes, Andrew wants to estimate the mean number of classes that students take at his university. He collects data from a randomly selected proportionate number of students from each grade level.
4. Yes, To estimate the mean salary of professors at his university, Homer collects data by recording the salaries of all professors included in 12 randomly selected departments.