Question

Two teaching methods and their effects on science test scores are being reviewed. A random sample of 12 students, taught in traditional lab sessions, had a mean test score of 75.6 with a standard deviation of 5.2. A random sample of 17 students, taught using interactive simulation software, had a mean test score of 84.3 with a standard deviation of 6.2. 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 be the mean test score for the students taught in traditional lab sessions and μ2 be the mean test score for students taught using interactive simulation software. Use a significance level of α=0.01

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

Ans:

pooled standard deviation=sqrt(((12-1)*5.2^2+(17-1)*6.2^2)/(12+17-2))=5.813

standard error for difference=5.813*sqrt((1/12)+(1/17))=2.192

Test statistic:

t=(75.6-84.3)/2.192

t=-3.969

df=12+17-2=27

p-value=tdist(3.969,27,1)=0.0002

As,p-value<0.01,reject the null hypothesis.

There is sufficient evidence to 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