An investigator wishes to determine whether alcohol consumption causes a dete-rioration in the performance of automobile drivers. Before the driving test, subjects drink a glass of orange juice, which, in the case of the treatment group, is laced with two ounces of vodka. Performance is measured by the number of errors made on a driving simulator. A total of 120 volunteer subjects are randomly assigned, in equal numbers, to the two groups. For subjects in the treatment group, the mean number of errors 1X equals 26.4, and for subjects in the control group, the mean number of errors 2X equals 18.6. The estimated standard error equals 2.4.

(a) Use t to test the null hypothesis at the .05 level of significance

(b) Specify the p-value for this test result.

(c) If appropriate, construct a 95 percent confidence interval for the true populationmean difference and interpret this interval. (d) If the test result is statistically significant, use Cohen'sd to estimate the effect size, given that the standard deviation, sp, equals 13.15. (e) State how these test results might be reported in the literature, given s1 = 13.99 and s2 = 12.15.