22. Hypothesis Test for Effects of Alcohol Refer to the sample data in Exercise 21 and use a 0.05 significance level to test the claim that there is a difference between the treatment group and control group. If there is a significant difference, can we conclude that the treatment causes a decrease in visual and motor skills?

x x

x x

Treatment Placebo Group Group n1
22 n2
22 1
4.20 2
1.71 s1
2.20 s2
0.72 x x 482 Chapter 9 Inferences from Two Samples