how to state the null hypothesis correctly?
that's very very confusing, the way to solve the problem is easy, but when I try to solve the exercises I always get it wrong not because it is easy to solve but always I am stating the null hypothesis in the wrong way I get everything right but the interpretation is always the opposite to that in the solution
As an alternative hypothesis, we state the desired and logical result we expect to obtain. For example, it is expected that a weight-loss program will help with losing weight, eating high-protein foods will help gain muscle, getting more sleep hours will help us be more productive, and so on.... The null hypothesis is a preliminary presumption that the changes obtained by the investigated variable is ineffective.
I have the same doubt: I have read on the PDF that the null hypothesis is "the status-quo. Everything which was believed until now
that we are contesting with our test". In my opinion what was believed until now is that that weight-loss program works well, it's the status-quo because it's what people expect from it. Isn't it? Why?