Critical value z score calculator8/29/2023 ![]() ![]() Statistical computing packages will produce the test statistic (usually reporting the test statistic as t) and a p-value. The hypotheses (step 1) should always be set up in advance of any analysis and the significance criterion should also be determined (e.g., α =0.05). In fact, when using a statistical computing package, the steps outlined about can be abbreviated. Statistical computing packages provide exact p-values as part of their standard output for hypothesis tests. The exact level of significance is called the p-value and it will be less than the chosen level of significance if we reject H 0. If the null hypothesis is rejected, then an exact significance level is computed to describe the likelihood of observing the sample data assuming that the null hypothesis is true. ![]() The final conclusion will be either to reject the null hypothesis (because the sample data are very unlikely if the null hypothesis is true) or not to reject the null hypothesis (because the sample data are not very unlikely). The final conclusion is made by comparing the test statistic (which is a summary of the information observed in the sample) to the decision rule. Here we compute the test statistic by substituting the observed sample data into the test statistic identified in Step 2. The complete table of critical values of Z for upper, lower and two-tailed tests can be found in the table of Z values to the right in "Other Resources."Ĭritical values of t for upper, lower and two-tailed tests can be found in the table of t values in "Other Resources." Rejection Region for Lower-Tailed Z Test (H 1: μ 1.960. The decision rule is: Reject H 0 if Z > 1.645. Rejection Region for Upper-Tailed Z Test (H 1: μ > μ 0 ) with α=0.05 The decision rules are written below each figure. Notice that the rejection regions are in the upper, lower and both tails of the curves, respectively. The following figures illustrate the rejection regions defined by the decision rule for upper-, lower- and two-tailed Z tests with α=0.05. For example, in an upper tailed Z test, if α =0.05 then the critical value is Z=1.645. The level of significance which is selected in Step 1 (e.g., α =0.05) dictates the critical value.
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |