Question: As part of a curriculum review, the psychology department would like to select a simple random sample of 40 of last year’s 200 graduates to obtain information on how graduates perceived the value of the curriculum. Describe two different methods that might be used to select the sample. (Select all that apply.)
1. **State the problem:** We need to select a simple random sample of 40 graduates from a total of 200 graduates.
2. **Definition of simple random sample:** A simple random sample means every individual has an equal chance of being selected, and the selection of one individual does not affect the selection of another.
3. **Method 1:** Number the 200 graduates from 1 to 200, use a random number generator to select 40 unique numbers, and choose those students.
- This method ensures each graduate has an equal chance of being selected.
4. **Method 2:** Group the graduates in sets of 5 and take one graduate from each group.
- Since 200 divided by 5 equals 40, selecting one graduate from each group of 5 ensures a total of 40 graduates.
- If the selection within each group is random, this method also approximates a simple random sample.
5. **Why other methods are not simple random samples:**
- Emailing the graduates and taking the first 40 responses is biased because it depends on who responds first.
- Calling the graduates and surveying the first 40 that answer is also biased for the same reason.
- Grouping the graduates in sets of 40 and taking one graduate from each group would only select 5 graduates total (since 200/40=5), which is not the required sample size.
**Final answer:** The two methods that might be used to select a simple random sample are:
- Number the 200 graduates from 1 to 200, use a random number generator to select 40 unique numbers, and choose those students.
- Group the graduates in sets of 5 and take one graduate from each group.