How did you calculate your sample size of 30 adult patients?

comment from the professor:
You chose the Knowledge to Action Framework to apply to your DNP project. Your organizational setting is described as a primary care clinic for adult patients with common chronic conditions. Approximately 30 patients are seen per day and about 1500 patients over a year. The population for your DNP project is described as adults aged 18 and older with a BMI of over 25.
– How did you calculate your sample size of 30 adult patients?
Your proposed data analysis plan consists of a paired t-test to compare pre-intervention and post-intervention patients’ weight.  The sample will be recruited at the clinic based on the exclusion and inclusion criteria and the craftiness of the patient to participate in your project. The inclusion and exclusion criteria are outlined, and Potential barriers that have been identified for your project include participants forgetting to input their data and lack of reliable mobile access. You have identified ways to mitigate patient barriers.
– What are you looking for in the results of your t-test?
– What are you describing using which descriptive statistics from your project’s data analysis.
*Attached is the whole work with the details of the project.
Instructions:
Use an APA 7 style and a minimum of 250 words. Provide support from scholarly sources. The scholarly source needs to be: 1) evidence-based, 2) scholarly in nature, 3) Sources should be no more than five years old (published within the last 5 years), and 4) an in-text citation. citations and references are included when information is summarized/synthesized and/or direct quotes are used, in which APA style standards apply. Include the Doi or URL link.
• Textbooks are not considered scholarly sources.
• Wikipedia, Wikis, .com website or blogs should not be use