Question

Two researchers conducted a study in which two groups of students were asked to answer 42 trivia questions from a board game. The students in group 1 were asked to spend 5 minutes thinking about what it would mean to be a​ professor, while the students in group 2 were asked to think about soccer hooligans. These pretest thoughts are a form of priming. The

200 students in group 1 had a mean score of 21.8

with a standard deviation of 3.5, while the 200 students in group 2 had a mean score of 19.9

with a standard deviation of 4.6.

Complete parts ​(a) and ​(b) below.

​(a) Determine the 95​% confidence interval for the difference in​ scores, μ1−μ2. Interpret the interval.

(b) What does this say about​ priming?

Answer 1

We need to construct the 95% confidence interval for the difference between the population means μ1​−μ2​. The following information has been provided about each of the samples:

The critical value for α=0.05 is . The corresponding confidence interval is computed as shown below:

Therefore, based on the data provided, the 95% confidence interval for the difference between the population means μ1​−μ2​ is 1.099<μ1​−μ2​<2.701, which indicates that we are 95% confident that the true difference between population means is contained by the interval (1.099,2.701).

(b)

It seems priming is successful. As 0 does not lie in the above confidence interval, priming can successfully alter and influence a person's opinions, in this case the output of a trivia game. (Goes a long way in saying, you think what you become!)

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