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1) What is the purpose of calculating a test statistic? How does this value desc

ID: 3251634 • Letter: 1

Question

1) What is the purpose of calculating a test statistic?  How does this value describe how the sample data either supports or contradicts a claim?

2) How does one decide between using a one-tailed or a two-tailed hypothesis test?  Is there an advantage to using one over the other?

3) We would like to compare the mean number of children per household in Country A to the mean number of children per household in Country B.  What procedure would be used to make such a comparison?  How would sample sizes be chosen?

4) A sample of 100 patients uses a new treatment for weight loss.  Describe how one would go about testing the claim that the weight loss treatment is effective.

5) What is the best predicted value for the response variable if there is no evidence of significant correlation in a sample?

Explanation / Answer

1. A test statistic is a statistic used in statisticalhypothesis testing. A hypothesis test is typically specified in terms of a test statistic, considered as a numerical summary of a data-set that reduces the data to one value that can be used to perform the hypothesis test.

Now, to contradict or support a claim we wll use t-test for hypothesis testing. If t statistic is less than critical t value then it is in rejection region and we can reject null hypothesis. if t statistic isn't in rejection region then we fail to reject null hypothesis.