I just uploaded a new video, "Samples, Sampling", to my YouTube channel. Here's the link to the video: https://youtu.be/bvglAgAZtXE. It is the first in a playlist on Samples. The other two videos will be about how to determine the Sample Size for Proportions and Count Date, and Sample Size for Measurement/ Continuous Data.
Here are the 6 Keys to Understanding the concept. This 17 minute video explains them in detail.
Andrew A. (Andy) Jawlik is the author of the book, Statistics from A to Z -- Confusing Concepts Clarified, published by Wiley.