
The left tail method, just like the right tail, has a cutoff point. We use left tail hypothesis testing to see if the z score is above the significance level critical value, in which case we cannot reject the Left tail hypothesis testing is illustrated below: There is left tail, right tail, and two tail hypothesis testing. There are 3 types of hypothesis testing that we can do. The smaller the significance level, the greater the nonrejection area. So the greater the significance level, the smaller or narrower the nonrejection area.

This means that there is a greater chance a hypothesis will be rejected and a narrowerĬhance you have of accepting the hypothesis, since the nonrejection area decreases. You increase the significance level, the greater area of rejection there is. If you choose a significance level of 20%, you increase the rejection area of the standard normal curve to 20% of the 100%. If you choose a significance level of 5%, you are increasing Of 1%, you are choosing a normal standard distribution that has a rejection area of 1% of the total 100%. Therefore, if you choose to calculate with a significance level The total rejection area of a normal standard curve. The significance level that you select will determine how broad of an area the rejection area will be. So when we do our testing, we see which hypothesis is actually true, the null (claimed) or the alternative (what we believe it is).

The alternative hypothesis is that μ > 20, which

In this case, the null hypothesis is the claimed hypothesis by the company, that the average complaints is 20 (μ=20). The alternative hypothesis is the hypothesis that we believe it actually is.įor example, let's say that a company claims it only receives 20 consumer complaints on average a year. The null hypothesis is the hypothesis that is claimed and that we will test against. We accept true hypotheses and reject false hypotheses. Whether we accept or reject the hypothesis. This Hypothesis Testing Calculator determines whether an alternative hypothesis is true or not.
