Statistics HELP- null and alternative hypothesis?

Nine students took the SAT. Their scores are listed below. Later on, they took a test preparation course and retook the SAT. Their new scores are listed below. Test the claim that the test preparation had no effect on their scores. Use 伪 = 0.05. Assume that the distribution is normally distributed.





What the null and alternative hypothesis be for this problem? It's confusing me.|||The null hypothesis in any experimental setting is going to be your prior expectation, in this case it is that "test preparation had no effect on their scores." In fact, our null hypothesis is almost always that our treatment had no effect. The alternative hypothesis is always that your null hypothesis is wrong, so in this case it is that test preparation did in fact have an effect on their scores.