How to determine sample size for a research

1. Assume you want to do a project that compares the survey results before an intervention to those after an intervention in the same sample (the same people will take both surveys). You plan to use a paired t-test to analyze your results. Using the “Determining the Appropriate Sample Size,” Topic Material, perform a sample size calculation to determine how large your sample should be. Justify your sample size calculation with citations. Discuss how your sample size may affect the validity of your study.

2. What you expect your sample size for your study to be? (my research will examine “Can a bladder training and timed-voiding program to help decreasing unassisted bathroom related falls in post stroke patients within eight weeks period on a rehabilitation hospital). How did you come up with this sample size?

at least 150 words to answer each question, with journal references published in last 5 years.