# Resolved: the null hypothesis

hello, assuming the company itself is saying that ajax + is better than ajax. so null hypo must be the difference between ajax + and ajax is > 0

in the example on excel its written that the null hypo is the difference between H ajax+ and H ajax < 0. how is that?

if 115 - 100 = 15 this means that ajax + is better than ajax this implies that what the company is stating about ajax + is right and so the null hypo must be H0 > 0 and me who wants to reject this statement must be H1 < 0

please if you could help with this. thanks

Hello,

In your case, the company claims that "Ajax+" is better than "Ajax." In hypothesis testing, we often set up the null hypothesis as the opposite or the negation of what we want to prove. So if you want to prove that Ajax+ is better (which means Ajax+ - Ajax > 0), your null hypothesis should be that Ajax+ is not better, or even worse, than Ajax (which means Ajax+ - Ajax ≤ 0).

Here’s how you might set it up:

1. Null Hypothesis (H0): Ajax+ is not better than Ajax. This means the difference (Ajax+ - Ajax) ≤ 0.

2. Alternative Hypothesis (H1): Ajax+ is better than Ajax. This means the difference (Ajax+ - Ajax) > 0.

In hypothesis testing, you try to reject the null hypothesis in favor of the alternative hypothesis. If your test results show that there is a significant difference such that Ajax+ is indeed better (and the difference is positive and statistically significant), then you reject the null hypothesis in favor of the alternative hypothesis.

However, if the test results are not significant, you do not have enough evidence to reject the null hypothesis, meaning you cannot confidently claim that Ajax+ is better based on your data.

In summary, your null hypothesis should be set up as the opposite of what you want to prove, to allow for a statistical test that either rejects this null hypothesis (supporting your claim) or fails to reject it (not supporting your claim).

Hope this helps!