Question

Two teaching methods and their effects on science test scores are being reviewed. A random sample of 16 16 students, taught in traditional lab sessions, had a mean test score of 80.8 80.8 with a standard deviation of 4.4 4.4 . A random sample of 14 14 students, taught using interactive simulation software, had a mean test score of 85.6 85.6 with a standard deviation of 5.1 5.1 . Do these results support the claim that the mean science test score is lower for students taught in traditional lab sessions than it is for students taught using interactive simulation software? Let μ1 μ 1 be the mean test score for the students taught in traditional lab sessions and μ2 μ 2 be the mean test score for students taught using interactive simulation software. Use a significance level of α=0.05 α = 0.05 for the test. Assume that the population variances are equal and that the two populations are normally distributed. Step 2 of 4 : Compute the value of the t test statistic. Round your answer to three decimal places.

Answer 1

	Sample 1	Sample 2
Mean	80.8	85.6
Standard Deviation	4.4	5.1
Count	16	14

The null hypotheiss to be tested is:

H0: The mean test score in the traditional lab sessions is the same as the mean test score in the interactive sessions, that is, μ1 -μ2=0

against the alternative hypothesis

H1: The mean test score in the traditional lab sessions is less than the mean test score in the interactive sessions, that is, μ1 - μ2 <>0

The test statistic to be used is:

Putting the values in the above expression we have:

The t-critical value for 0.05 level of significance and 28 degrees of freedom is .

Since the t-statistic value is less that the left tail critical value there is sufficient evidence to reject the null hypothesis.

Thus, it can be concluded that the mean test score in the traditional lab sessions is less than the mean test score in the interactive sessions.