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Problem 2


9.6 t-Test to Compare Two Population Means: Independent Samples (Unequal Variances)

Does alcohol impair your visual/motor skills?  Two randomly selected groups of 20 people were given either alcohol to drink or placebo, and they then had their visual and motor skills tested.  Those who drank alcohol made an average of 4.3 errors with a standard deviation of 2.5 errors.  Those who drank the placebo made an average of 1.7 errors with a standard deviation of 0.7 errors. Use a 0.02 significance level to test the claim that there is a difference between the two groups (Do not assume equal variances).  Does alcohol lead to more mistakes? 


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