A Researcher is interested in whether the effectiveness of a

A Researcher is interested in whether the effectiveness of a new advertising program that encourages more exercise is impacted by gender (i.e., male versus female) or socioeconomic status (SES), which has been categorized into low, medium, and high groups. After the advertising has been in place for a year, the Researcher asks study participants about the average amount of weekly exercise they have engaged in for the past three months. She uses a fully-crossed design so that she randomly surveys 21 subjects from each of the gender-SES conditions.

a) Complete the degrees of freedom for each entry in the ANOVA table.

b) A teacher is interested in conducting research that examines the effectiveness of four types of classroom curricula. After running an ANOVA and finding that there are differences in the effectiveness of the curricula on student test scores, she runs a Tukey test, which gives her the following output to the right. What can you conclude about the pairwise comparisons of mean tests using the 95% confidence intervals?

Solution

degree of freedom between groups =3-1 =2

Within groups =20-2 = 18

Total =21-1=0

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Curriculum 1 - currilculum 2 confidence interval contains 0.

Hence Mean I = mean 2 is statistically evident.

Similarly curriculum 2 and currciculum 3 have the same average as conf interval contains 0.