A psychologist is interested in whether working memory is influenced by sleep loss. A total of 115 participants was utilized for the study. The psychologist divides the participants into two groups, and she administers a measure of working memory to the participants in each group. The participants in one group (N₁ = 57) were kept awake for the entire night, and the participants in the second group (N₂ = 58) maintained their normal sleep schedule.

1. Identify the population of interest.
2. Identify the sample.
3. Identify the independent variable(s).
4. Identify the dependent variable(s).
5. State the null hypothesis.
6. State the research hypothesis.
7. What statistical test would we use to determine whether there is a significant difference between the groups? Explain your answer.