Citing research papers and articles from journals in your Statistics Optional answers is crucial for providing evidence and credibility to your arguments. By citing these sources, you acknowledge the original authors' work and allow readers to verify the information you present. Here's a detailed explanation on how to cite research papers and articles from journals in your answers:

1. Start with the Author(s) and Title:
- Begin the citation with the last name of the author(s) followed by their initials.
- If there are multiple authors, separate their names using commas.
- After the author(s), include the title of the research paper or article in quotation marks.

2. Include Publication Information:
- Provide the name of the journal where the paper or article was published in italics.
- Include the volume number and issue number of the journal (if applicable).
- Specify the page range of the paper or article within the journal.

3. Add Publication Date:
- Mention the year of publication in parentheses after the title of the research paper or article.
- If available, include the month and day as well.

4. Provide the Digital Object Identifier (DOI):
- If the research paper or article has a DOI assigned to it, include it at the end of the citation.
- A DOI is a unique alphanumeric string assigned to a digital object, ensuring its persistent linkability.

5. Format the Citation:
- There are different citation styles, such as APA, MLA, and Chicago. Follow the style recommended by your institution or instructor.
- Each citation style has specific guidelines for formatting and punctuation.
- Ensure consistency in formatting throughout your answers.

Example citation in APA style:

Smith, J. D., & Johnson, A. B. (2022). "The Impact of Sample Size on Statistical Inference." Journal of Statistics, 15(2), 102-118. doi: 10.1234/exampledoi

Remember to adapt the citation style, author names, title, publication information, and DOI to match the specific research paper or article you are citing.

By following these guidelines, you can effectively incorporate research papers and articles from journals into your Statistics Optional answers while maintaining academic integrity and providing proper attribution to the original sources.