A hypothesis states a difference exists between two populations. Sometimes this is an obvious conclusion because the means will be very different. For example, if I gave math tests to boys and girls and the boys on average scored 20 points better than the girls, I know that is enough of a difference to conclude with accuracy that boys are in fact better in math than girls. And I know that a mere 1 or 2 point difference is not enough of a difference to conclude that boys or girls are better. But what if the difference is 5 or 10 points - is that enough of a difference? Now it is not so obvious = and that's why we need to do the t-test.
Can someone give me an example of when you thought something mattered - that it made a difference, but later you were surprised to learn that what you thought mattered, did not? Or an example of time when something did not matter, when in fact, all along it did?
Suppose that I live in a neighbourhood that is apparently posh, highly prized and the people living there are relatively rich. I have now accepted an offer for Bachelor's degree in a university in nearby town, which is in the countryside and relatively poorer. I thought that I could easily get away by paying very low rental for a studio-type accommodation next to the university. With this ...
This solution provides an example of a situation in which the a difference between two populations is compared.