QA2

The alternative hypothesis used in anova is U1=U2=U3

( false)

If an ANOVA test is conducted the null hypothesis is rejected. what does this indicates?

A difference between least one pair of population means

Which of the folllowing description of ANOVA is correct?

ANOVA is used to compare two or more means

Which of the following is correct?

An ANOVA conducted on a design in which there is only one factor is called a one-way ANOVA.

If a confidence interval for the difference between a pair of treatment means includes 0, then we reject the null hypothesis that there is no difference in the pair of treatment means.

False

If the MSE and MSB are approximately the same, it is highly likely that population means are different

False

The omnibus null hypothesis when performing an analysis of variance is that there are difference between group means; however no prediction is made concerning where the differences lie

False

Unlike t tests, an ANOVA uses both differences between group means and differences whether or not the differences are significant

False

You want to make a strong case that the different groups you have tested come from populations with different means. Your case is strongest when

MSB/MSE is high

The shape of the F-statistic distribution is

Positive skewed

An electronics company wants to compare the quality of their cell phones to the cell phones from three competitors. They sample 10 phones from each company and count the number of defects for each phone. If anova were used to compare the average number of defects, then the levels would be defined as:

The four companies

Which of the following assumptions is not required to conduct an ANOVA test?

The populations have the same mean for the variable of interest

Which best describes the assumptions of homogeneity of variance?

The variances in the populations are equal

For an ANOVA test, rejection of the null hypothesis does not identify which treatment means differ significantly.

True

In a two-way ANOVA with interaction, there are two factor effects and an interaction effect.

True

To employ ANOVA, the populations being studied must be approximately normally distrubuted

True

To employ ANOVA, the populations should have approximately equal standard deviations

True

Unlike t tests, an ANOVA may be used to test for difference among more than 2 groups

True

When performing a one-factor ANOVA (between subjects), it is important that each subject only provide a single value. If a subject were to provide more than one value, the independence of each value would be lost and the test provided by an ANOVA would not be valid.

True

An F statistic is:

a ratio of two variances

In a two-way ANOVA with interaction, a significant interaction term indicates that

both factors have a combined effect on the response variable

When the null hypothesis is rejected in ANOVA, the ANOVA test reveals which means are significantly different from which other means

fasle

Analysis of variance is used to

simultaneously compare several population means