Deck 18: Analysis of Variance and Experimental Design

Question 1

Moriah runs a one-way ANOVA to test differences in means in delivery time.The SSB is 109,400 and the total sum of squares is 715,460.What is the value of the SSW?

A)-606,060
B)218,800
C)606,060
D)824,860

Answer 1

606,060

Question 2

In a one-way ANOVA test,we conclude there are differences across population means if the

A)between variation is small relative to the within variation.
B)between variation and within variation are equal.
C)between variation is large relative to the within variation.
D)between variation equals zero.

Answer 2

between variation is large relative to the within variation.

Question 3

In two-way ANOVA,a single variable is measured at various levels of a single factor.

Answer 3

False

Question 4

In a designed experiment,researchers control for various factors such as age,gender,or socioeconomic status.

Question 5

There are only two possible ANOVA procedures: one-way ANOVA and two-way ANOVA.

Question 6

The null hypothesis that indicates there are no differences in population means across levels is H₀: µ₁= µ₂=… µ_J.

Question 7

What is one assumption of two-way ANOVA tests?

A)The distribution is not normal and the variances are different across combinations.
B)The distribution is normal and the variance at any particular combination is the same as any other combination.
C)The distribution is not normal and the variance at any particular combination is the same as any other combination.
D)The distribution is normal and the variances are different across combinations.

Question 8

The smaller the p-value in an ANOVA table,the greater the likelihood that the effect

A)is statistically insignificant.
B)will be ignored.
C)is statistically significant.
D)has no practical impact.

Question 9

Samples with large within variation have boxplots with _____ boxes and _____ lines extending from them.

A)wide,long
B)wide,no
C)short,no
D)short,short

Question 10

An observational study

A)analyzes data already available.
B)makes it possible to rule out factors over which the researcher has no control for the observed effects.
C)examines individuals that have been selected by the researchers.
D)allows researchers to control for all extraneous factors.

Question 11

The ANOVA test statistic is the z-ratio.

Question 12

Contrast is the unavoidable confusion of some effects with others in an incomplete experimental design.

Question 13

Priti is wondering whether time of day impacts worker productivity.She randomly chooses 25 workers from each of the three shifts her company runs.The design of this study is

A)even.
B)balanced.
C)unbalanced.
D)observational.

Question 14

In a full factorial design,researchers assign experimental units to each treatment level combination.

Question 15

The essence of the ANOVA procedure is that we compare the variation within the individual treatment levels to the variation between the sample means.

Question 16

To perform ANOVA with regression,we run a regression with the same dependent variable as in ANOVA and use dummy variables for the treatment levels as the only explanatory variables.

Question 17

Jeremiah is testing the impact of different fertilizers on crop yields.Six different fertilizers have been applied to one field.Suppose he uses an ANOVA to test whether or not there are differences in yields.How many treatments are in this test?

A)zero
B)one
C)five
D)six

Question 18

Which p-value from a two-way ANOVA table indicates an effect that is not statistically significant?

A)0.000
B)0.011
C)0.047
D)0.110

Question 19

The dependent variable is also known as the response variable or criterion variable.

Question 20

Bonferroni,Tukey,and Scheffe methods are three methods that expand confidence interval lengths to correct for the multiple comparison problem.

Question 21

What is the interpretation of the R² value given in regression output?

A)R² is the percentage of the variation of the dependent variable explained by the various treatment levels of the single factor.
B)R² is the percentage of the variation of the explanatory variable explained by the various treatment levels of the single factor.
C)R² is the percentage of the variation of the dependent variable explained by the various treatment levels of the multiple factors.
D)R² is the percentage of the variation of the explanatory variable explained by the various treatment levels of the multiple factors.

Question 22

In a one-way ANOVA we are testing for equality of

A)population means.
B)population proportions.
C)population variances.
D)population standard deviations.

Question 23

Confidence intervals get wider as we move from

A)no correction,to Bonferroni,to Sheffe,to Bonferroni.
B)Sheffe,to Tukey,to Bonferroni,to no correction.
C)Tukey,to Sheffe,to Bonferroni,to no correction.
D)no correction,to Tukey,to Bonferroni,to Sheffe.

Question 24

Interactions

A)indicate patterns of differences in means that could not be guessed from the main effects alone.
B)occur only in one-way ANOVA tests.
C)occur when the effect of one factor on the dependent variable is independent of the level of other factors.
D)indicate the effect of one factor on the dependent variable is the same regardless of the level of the other factors.