•What is the difference between a critical value and a test statistic? •Decide w
ID: 2960510 • Letter: #
Question
•What is the difference between a critical value and a test statistic?•Decide whether you should use a normal sampling distribution or a t-sampling distribution to perform the hypothesis test.
•Why would you use a z-test rather than a t-test?
•Which do you think you will use more often? Justify your decisions.
•Then use the distribution to test the claim.
•Write a short paragraph about the results of the test and what you can conclude about the claim.
Explanation / Answer
*a critical value is what the test statistic must be greater/less than to reject the null. The test statistic is the actual observed. *Well, I would use a t-test. Which is why I'm unsure about your third question. I would use a t-test because I don't know the standard deviation of the population. I would use a t-test more often, because I never will know the standard deviation of the population. Test statistic: (21-19)/(4/sqrt(5))=1.11803399 1 tailed t test. P(t>1.11803399 for n=4)=.16 I would not reject the null hypothesis. The pvalue is not below any common significance levels so it is plausible that the gas mileage is at least 21 mpg.