Most of the statistics you have covered have been concerned with null hypothesis testing:

Most of the statistics you have covered have been concerned with null hypothesis testing: assessing the likelihood that any effect you have seen in your data, such as a correlation or a difference in means between groups, may have occurred by chance. As we have seen, we do this by calculating a p value -- the probability of your null hypothesis being correct; that is, p gives the probability of seeing what you have seen in your data by chance alone. This probability goes down as the size of the effect goes up and as the size of the sample goes up.Can you provide a more comprehensive example of this?

Can anyone help with the presented questions above?