In the t test for independent groups, ____.

we estimate µ1 µ2

we estimate 2


we estimate X1-X2 

df = N  1
Exhibit 14-1

A professor of women’s studies is interested in determining if stress affects the menstrual cycle. Ten women are randomly sampled for an experiment and randomly divided into two groups. One of the groups is subjected to high stress for two months while the other lives in a relatively stress-free environment. The professor measures the menstrual cycle (in days) of each woman during the second month. The following data are obtained.
High stress
20
23
18
19
22
Relatively stress free
26
31
25
26
30








Refer to Exhibit 14-1. The obtained value of the appropriate statistic is ____.

tobt = 4.73

tobt = 4.71


tobt = 3.05

tobt = 0.47
Refer to Exhibit 14-1. The df for determining tcrit are ____.

4

9


8

3
Refer to Exhibit 14-1. Using  = .052 tail, tcrit = ____.

+2.162

+2.506


±2.462

±2.306


Refer to Exhibit 14-1. Using  = .052 tail, your conclusion is ____.

accept H0; stress does not affect the menstrual cycle

retain H0; we cannot conclude that stress affects the menstrual cycle


retain H0; stress affects the menstrual cycle

reject H0; stress affects the menstrual cycle
Refer to Exhibit 14-1. Estimate the size of the effect.  = ____

0.8102

0.6810


0.4322

0.5776
A major advantage to using a two condition experiment (e.g. control and experimental groups) is ____.

the test has more power

the data are easier to analyze


the experiment does not need to know population parameters

the test has less power
Which of the following tests analyzes the difference between the means of two independent samples?

correlated t test

t test for independent groups


sign test

test of variance
If n1 = n2 and n is relatively large, then the t test is relatively robust against ____.

violations of the assumptions of homogeneity of variance and normality

violations of random samples


traffic violations

violations by the forces of evil




Exhibit 14-3

Five students were tested before and after taking a class to improve their study habits. They were given articles to read which contained a known number of facts in each story. After the story each student listed as many facts as he/she could recall. The following data was recorded.
Before
10
12
14
16
12
After
15
14
17
17
20








Refer to Exhibit 14-3. The obtained value of the appropriate statistic is ____.

3.92

3.06


4.12

2.58
Refer to Exhibit 14-3. What do you conclude using  = 0.052 tail?

reject H0; the class appeared to improve study habits

retain H0; the class had no effect on study habits


retain H0; we cannot conclude that the class improved study habits

accept H0; the class appeared to improve study habits
Which of the following is (are) assumption(s) underlying the use of the F test?

the raw score populations are normally distributed

the variances of the raw score populations are the same


the mean of the populations differ

the raw score populations are normally distributed and the variances of the raw score populations are the same
If its assumptions are met, the analysis of variance technique is appropriate when ____.

two or more factors are varied

several levels of a single independent variable are compared


three or more groups are involved

all of the other three options
A major limitation of a two group design is that ____.

we can’t run enough subjects

very often, two groups are insufficient for a clear interpretation


the population parameters may not be applicable

the means between groups may not differ
sB2 is a measure of ____.

2 alone

2 + the effects of the independent variable


the variability between the means

2 + the effects of the independent variable and the variability between the means
The total degrees of freedom for an experiment with n1 = 10, n2 = 12, and n3 = 10 is ____.

2

32


31

29
Exhibit 15-3

Pertain to the following data.



Refer to Exhibit 15-3. What is the value of Fobt?

5.67

6.53


1.95

3.26



Refer to Exhibit 15-3. What is the value of Fcrit ? Use  = 0.05.

5.14

4.76


4.46

4.07
Refer to Exhibit 15-3. What is your conclusion? Again use  = 0.05

retain H0

reject H1


reject H0

accept H0
Refer to Exhibit 15-3. Using , the estimated size of effect is ____.

22.6% of the variability

52.8% of the variability


43.6% of the variability

55.1% of the variability
Refer to Exhibit 15-3. Using  2, what is the estimated size of effect?

0.7232

0.6852


0.6582

0.6312
What is the value of SST if SSB = 236 and SSW = 54?

290

182


4.37

100
By doing multiple t tests when there are more than 2 experimental groups we increase the risk of making what kind of mistake?

accepting H0

Type I error


Type II error

all of the other three options
If  = 46,  = 50,  = 92 and n1 = n2 = n3, what is the value of ?

cannot be determined from information given

50.0


188.0

62.67
If SSW = 126, N = 28, k = 4, then what is the value of sW2

cannot be determined from information given

5.25


42.0

4.667
If dfB = 3 and dfT = 29 and Fobt = 3.15, what would you conclude using  = 0.05?

reject H0

reject H1


retain H0

retain H1
If sB2 = 27.9 and sW2 = 54.2, what is the value of Fobt?

impossible result, there must be an error

1.94


0.51

2.76
A priori comparisons ____.

are planned in advance of the experiment

often arise out of theory and prior research


may be done without obtaining a significant Fobt in the one-way ANOVA

all of the other three options
Chi-square is used to test differences between ____.

proportions

means


variances

none of the other three options
The sampling distribution of chi-square is ____.

skewed

varies with df


is a theoretical distribution

all of the other three options
A contingency table ____.

is a two-way table

involves two variables


involves two mutually exclusive variables

is a two-way table and involves two variables
The computation of fe ____.

is based on population proportion estimates

is based on known population proportions


is based on population means

none of the other three options
If N = 18 and  = 0.052 tailed, the value of Tcrit is ____.

40

39


41

47
If  = 0.05, and df = 4, the value of 2crit = ____.

9.488

0.711


7.815

11.070


Exhibit 17-1

Prior to a recent gubernatorial election, a survey was conducted to determine whether there was a relationship between sexual gender and preference for the Democratic or Republican candidate. The following data were recorded.



Refer to Exhibit 17-1. The value of 2obt = ____.

2.06

2.09


1.80

1.75
Refer to Exhibit 17-1. The value of df = ____.

2

1


3

need more information
Refer to Exhibit 17-1. Using  = 0.05, 2crit = ____.

3.841

5.412


2.706

3.841
Refer to Exhibit 17-1. Using  = 0.05, what is your conclusion?

accept H0; there is no relationship between sex and candidate preference

reject H0; there is a significant relationship between sex and candidate preference


retain H0; the study does not show a significant relationship between sex and candidate preference

retain H0; this study shows a significant relationship between sex and candidate preference
As the separation between the two groups of scores increases, Uobt ____.

increases

decreases


stays the same

approaches Uobt
The statistics (U or U’) used in the Mann-Whitney U test, measure ____.

the differences between the means of the two groups

the direction of the differences between pairs of scores


the power of the experiment

the separation between the two groups
If n1 = 6, n2 = 8 and  = 0.052 tail, Ucrit value is ____.

8

40


6

42
The Mann-Whitney U test is used with ____.

an independent groups design

a replicated measures design


a correlated groups design

none of the other three options
Using SPSS, the appropriate steps to analyze data for student’s t test for correlated groups are _________

Compare Means > Paired Sample t test > Before_C > After_C

Analyze > Compare Means > Paired Sample t test > After_C > Before_C


Analyze > Compare Means > Paired Sample t test > Before_C > After_C

Analyze > Compare Means > Before_C > After_C
In SPSS, the results of analysing data for student’s t test are displayed   ____.

in a graph

in a number of tables


as a stem and leaf

in a histogram
In SPSS, the appropriate steps to analyze data for a one-way ANOVA are ____.

you cannot perform ANOVA in SPSS

One-Way ANOVA >Analyze > Compare Means


Compare Means > One-Way ANOVA

Analyze > Compare Means > One-Way ANOVA
In SPSS, when you follow the steps to perform one-way ANOVA,  ____.

you will not be given the option to compute “descriptive statistics”

you will  be given the option to compute “descriptive statistics”


you will  be given the option to compute “descriptive statistics”, but you have to open a new file

you will  be given the option to compute “descriptive statistics”, but you have to restart SPSS