SOLUTION: Even though the population standard deviation is unknown, an investigator uses 'z' rather than the more appropriate 't' to test a hypothesis at the level .05 level of significance.

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Question 1081089: Even though the population standard deviation is unknown, an investigator uses 'z' rather than the more appropriate 't' to test a hypothesis at the level .05 level of significance.
a) is the true value of significance larger or smaller than .05?
b) Is the true critical value larger or smaller than that for the critical 'z'?
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
Using the z will result in a smaller critical value which means that the p-value will be smaller than it really is. Essentially, one is moving the critical value closer to the mean than it should be. This means that for a given significance with the z, say 0.05, the true value is somewhat more than 0.05
The true critical value will be larger than for z.