Question

Even though the population standard deviation is unknown, an investigator uses z rather than the more appropriate t to test a hypothesis at the .05 level of significance. (a) Is the true level of significance larger or smaller than .05? (b) Is the true critical value larger or smaller than that for the critical z?

Answer 1

a) if the true level of significance is smaller than 0.05 then we reject the null hypothesis and if true level of significance larger than 0.5 then we don't reject the null hypothesis.

b) if true critical value is larger than the critical z then we reject the null hypothesis and if it is less than critical z value then we accept or do not reject the null hypothesis.