Question

The University Health Center is interested in understanding if there is a difference in the mean number of alcoholic drinks consumed by Criminology and Sociology (no-double majors) students in a month.

	Size	Mean	Variance
CRIM Majors	27	13.3	4.2
SOCI Majors	22	7.5	2

(1)Which test will you use? What are the null and research hypotheses? Directional?

(2)Calculate the obtained value below (show work). The analyst wants to restrict the probability of random chance and set a probability value of 0.05.

(3)Based on the critical value and the obtained value, what can you conclude about the mean number of drinks by Criminology and Sociology students?

Answer 1

1) We will two-sample-t-test .

It is a two-tailed test. So it is a non-directional test.

2) The test statistic is

  

= 11.68

3)

          

          = 45

At 0.05 significance level, the critical values are +/- t_0.025 = +/- 2.014

Since the test statistic value is greater than the positive critical value (11.68 > 2.014), so we should reject the null hypothesis.

At 0.05 significance level, we can conclude that the mean number of drinks by Criminology and Sociology students are different.