To determine whether the differences between group means are statistically significant, analysis of variance examines the differences _________.

	A.	neither within nor between groups
	B.	between and within groups
	C.	within groups
	D.	between groups

What is the null hypothesis when doing the analysis of variance procedure?

	A.	all of the group means are significantly different from each other in the population
	B.	at least one of the group means in the population is different from the others
	C.	the sample means are the same for all of the groups
	D.	none of the group means in the population is different from each other

If we conduct an analysis of variance and our F test statistic has a probability (p value) of less than .05, what can we conclude?

	A.	There is more variance within groups than there is between groups
	B.	We cannot reject the null hypothesis
	C.	In the population, at least one of the group means is different from the others
	D.	In the population, the group means are not significantly different from each other

Below are the results of a Tukey post-hoc test for an analysis of variance where socioeconomic status (high, medium, low) is the independent variable, and score on a writing test is the dependent variable.

Tukey multiple comparisons of means 95% family-wise confidence level Fit: aov(formula = write ~ ses) $ses diff lwr upr p adj medium-low 1.309295 -2.6052575 5.223847 0.7096950 high-low 5.296772 0.9887256 9.604818 0.0114079 high-medium 3.987477 0.3296892 7.645265 0.0289035

Based on the results, we can conclude ____________

	A.	all three socioeconomic groups are significantly different from each other
	B.	the high socioeconomic group has the highest average writing test score and is significantly different from the middle and low groups
	C.	there is no difference between the three group means
	E.	the medium and low socioeconomic groups are significantly different from each other and the medium group has the higher average writing test score