For example: I wanted to look at the difference between the length of stay for Procedure A done on Monday versus Friday. I can calculate a t-test easy enough, but I don't know how to figure out if my

*n*is large enough to find a significant difference. I know how many roughly are done per year across the country, I know how many are done at our institution per year. I know the average length of stay at our institution as well as nationally. I'm just not sure how to go about this. Any advice would be helpful.

The link below is helpful, but I'm not entirely sure I know how to provide the proper population size.

https://www.qualtrics.com/blog/calculating-sample-size/