An experiment was conducted to test the effects of alcohol. The errors were recorded in a test of visual and motor skills for a treatment group of people who drank alcohol and another group given nonalcoholic drink. The results are shown below. The populations from which the sample are drawn are normally distributed. Conduct a hypothesis test at a 5% significance level to see if there is a difference between the mean errors for each group.
Treatment Placebo
x1 = 3.2 x2 = 1.71
s1 = 2.2 s2 = 0.72
n1 = 28 n2 = 28