QUIZ 5

Quiz 5



Quiz 5

1. If SST = 56 and SSB = 14, SSW = _42_.

a. 34

b. 6

c. -6

d. 42

2. If dfB = 4 and dfW = 20, using alpha = 0.05, Fcrit = _________.

a. 2.87

b. 3.10

c. 3.74

d. 6.22

3. An investigator conducts an experiment involving the effects of three levels of a drug on memory. Subjects are randomly assigned to one of three conditions. A different drug level is administered in each condition. Memory is measured 10 minutes after each subject receives the drug. The following scores are recorded. The higher the score, the better the memory. Drug Level onetwothree

6914

5713

8915

21319

After conducting a one-way ANOVA of the above data, which of the following is the variability among the group means 15.5 .

ANOVA

VAR00002

Sum of Squares

df

Mean Square

F

Sig.

Between Groups

201.500

2

100.750

15.500

.001

Within Groups

58.500

9

6.500

Total

260.000

11

a.6.50

b.15.5

c.100.75

d.201.5

4. Refer to the drug study. After conducting a one-way ANOVA of the above data, which of the following is the average variance within each of the three groups.

a. 6.50

b. 15.5

c. 100.75

d. 201.5

5. Refer to the drug study. After conducting a one-way ANOVA of the above data, which of the following is the F critical using alpha at 0.05.

a. 3.63

b. 4.26

c. 5.12

d. 4.46

6. If I have four groups, and a total of 40 subjects in the entire experiment, how many within groups degrees of freedom do I have.

a. 39

b. 3

c. 36

d. 28

7. Refer to the drug study. When calculating the total sum of squares, I utilize the following expression: SStotal = 1460 - (120)2/12 which equals 260. The SS between = (21)2/4 + (38)2/4 + (61)2/4 - (120)2/12 which equals 201.5. Based on this information which of the following is the numerator of the average variance within each group.

a. 1460

b. 201.5

c. 120

d. 58.5

8. Refer to the drug study. When calculating the total sum of squares, I utilize the following expression: SStotal = 1460 - (120)2/12 which equals 260. The SS between = (21)2 + (38)2 + (61)2 - (120)2/12 which equals 201.5. Based on this information which of the following is the numerator of the total variance among all the scores.

a. 1460

b. 201.5

c. 120

d. 260.

9. Refer to the drug study Estimate the size of the effect. Using omega squared.

a. 0.5109

b. 0.6698

c. 1.6633

d. 0.7073

? 2 = (SSB-(k-1)MS within)

(SSt+MS within)

? 2

=

100.75

260

+

58.5

? 2

=

100.75

318.5

? 2

=

0.316

10. Refer to drug study. Estimate the size of the effect using Cohen's f.

a. 1.4244

b. 0.6698

c. 1.6633

d. 1.5546

Cohen's FSQRT (k-1)(MSbet-MSwith) knMSwith

Cohen's F

=

SQRT

(2) * (201.5 - 58.5)

 

 

260

+

58.5

Cohen's F

=

SQRT

2

143

318.5

Cohen's F

=

SQRT

286.000

Cohen's F

=

16.91



11. A sleep researcher conducts an experiment to determine whether sleep loss affects the ability to maintain sustained attention. Fifteen individuals are randomly divided into the following three groups of 5 subjects each: group 1, which gets the normal amount of sleep (7-8 hours); group 2, which is sleep-deprived for 24 hours; group 3, which is sleep-deprived for 48 hour. And group 4 which is sleep deprived for 72 hours. All four groups are tested on same auditory vigilance task. Subjects are presented with half-second tones spaced at irregular intervals over a 1-hour ...