RES 342 Research And
Evaluation II
FINAL EXAM
1.
What are the
critical z-values for a two-tailed hypothesis test if the significant level =
0.01?
a. ± 1.96
b. ± 2.33
c. ± 2.58
d. ± 1.65
2.
In classical
hypothesis testing, the test statistic is to the critical value what the
__________.
a. ‘p-value’ is to alpha
b. critical value is to alpha
c. test statistic is to the ‘p-value’
d. level of significance is to the test statistic
3.
For a
hypothesis test of a single population mean at 95% confidence level, a
calculated Z score of 1.7 supports the conclusion that
a. the population mean is greater than the hypothesized
value
b. the null hypothesis cannot be rejected
c. the sample is biased
d. the population mean is less than expected
4.
If the paired
differences are normal in a test of mean differences, then the distribution
used for testing is the
a. normal distribution
b. chi-square
c. student distribution
d. F distribution
5.
One hundred
women were polled and 60 reported successfully communicating an automobile
problem to an auto repairman. A sample of 150 men had 95 reporting the same
success. The value of the test statistic for a test of the equality of
proportions is
a. -0.5319
b. 0.7293
c. -0.419
d. 0.2702
6.
Weekly sales
of iPods® at 20 Best Buy® stores are compared before and after installing a new
eye-catching display. To determine if the display is effective in increasing
sales, what type of statistical test would you perform?
a. Comparison of means using independent samples using a
t-test
b. Comparison of proportions using independent samples
using a z-test
c. Comparison of means using a paired z-test
d. Comparison of means using a paired t-test
7.
When is it
appropriate to use the paired difference t-test?
a. Four samples are compared at once.
b. Any two samples are compared.
c. Two independent samples are compared.
d. Two dependent samples are compared.
8.
A survey of
hotels found that the average hotel room rate in New Orleans is $88.42 and the
average room rate in Phoenix is $80.61. The survey sampled 50 hotels in each
city. The standard deviations were $5.62 and $4.83, respectively. At alpha=.05,
it can be concluded that there is a significant different in the rates?
a. 7.45
b. -1.96
c. 1.96
d. -7.45
9.
If the paired
differences are normal in a test of mean differences, the distribution used for
testing is the
a. normal distribution
b. chi-square
c. student t distribution
d. F distribution
10.
The
accountant for Thomas’s Furniture Store is concerned regarding the outstanding
receivable owed the company. There has been a cash flow problem and it is
believed that the slow collection of accounts receivable is partially the
blame. The accountant believes that 40% of the present accounts are more than 4
months behind in making payments. To be able to make a decision regarding this
belief, a random sample of 100 accounts was taken. It was found that 37
accounts were more than 4 months late. Did the sample data confirm the
accountant’s belief? Use the .05 significant level for the statistical test.
a. There is not enough evidence to confirm or deny the
belief.
b. The accountant's belief is not confirmed.
c. The accountant's belief is confirmed.
d. The accountant needed to take a larger sample.
11.
New college
business graduates are finding it difficult to get a job. A business journal
has reported that only one in five graduates is able to find a job within 6
months of their graduation. A report by University of Phoenix indicated that
out of a survey of 300 recent business graduates, 75 had jobs. You are a
business major at University of Phoenix and have a concern about getting a job.
Based on this data, will a graduate of University of Phoenix have a better
chance of getting a job in the first 6 months after graduation? Use the .05
significant level for the test.
a. No, there is not a significant difference.
b. It cannot be predicted based on this data.
c. Yes, there is a significant difference.
d. The business journal information is incorrect.
12.
Analysis of
variance (ANOVA) is used to
a. compare nominal data
b. compute t- test
c. compare population proportion
d. simultaneously compare several population means
13.
Mr. Thomas
owns three different restaurants in Cincinnati, Ohio. He is concerned about the
profitability of the restaurants. There are monthly differences between the
restaurants and he wants to determine if the differences in profit are
significant. Mr. Thomas wants to do a statistical test to see if he should be
concerned. The best test to address this problem would be
a. a paired t- test
b. two different t tests
c. an ANOVA test
d. a two sample test
14.
Sound
engineers studied factors that might affect the output, in decibels, of a rock
concert’s speaker system. The desired level of significance was a = .05. The
results of their ANOVA tests are shown:
Source of Variation
SS df MS F
P-value
Amplifier
99.02344 99.02344 0.005718
Position
93.98698 31.32899 3.215807
0.051003
Interaction
10.15365 3 3.384549
0.347412 0.791505
Error
155.875 16 9.742188
Total
359.0391 23
The interaction between the Position and Amplifier
treatments was
a. very significant
b. slightly significant
c. insignificant
d. highly correlated
15.
Totto, an
automobile manufacturer, has designed a radically new engine and wants to
recommend the grade of gasoline that will have the best fuel economy. The four
grades are regular, below regular, premium, and super premium. The test car
made three trial runs on the test track using each of the grades and the miles
per gallon were recorded. At the 0.05 level, what is the critical value of F
used to test the hypothesis that the miles per gallon for each fuel are the
same?
a. 1.96
b. 4.07
c. 2.33
d. 12.00
16.
If an ANOVA
test is conducted and the null hypothesis is rejected, what does this indicate?
a. Too many degrees of freedom
b. A difference between at least one pair of population
means
c. No difference between the population means
d. The variances are the same
17.
Nonparametric
statistics are used when
a. you have qualitative data, with your variables being
measured at the nominal or interval level
b. you have qualitative data, with your variables being
measured at the ordinal or ratio level
c. you have qualitative data, with your variables being
measured at the nominal or ordinal level
d. you have qualitative data, with your variables being measured
at the ordinal or interval level
18.
The
nonparametric test most commonly used for testing the statistical independence
between two variables is
a. the Kruskal- Wallis test
b. the Chi- Square test
c. the Mann Whitney test
d. the Sign test
19.
What
nonparametric test is used when the assumptions for the parametric ANOVA cannot
be met? Its purpose is to test whether three or more populations are equal. The
data must be at least ordinal scaled.
a. Students’ t
b. Kruskal- Wallis
c. Mann-Whitney
d. ANOVA
20.
Rachael Smith
is the personnel manager at Johnson and Johnston, an accounting firm. She is
concerned about absenteeism, which seems to be an increasing problem,
especially after days off work. She decided to sample the records to determine
if absenteeism was distributed evenly throughout the 6-day work week. The null
hypothesis to be tested was: Absenteeism is distributed evenly throughout the
week. The sample results were:
Day of Week
Number Absent
Monday 12
Tuesday 9
Wednesday 11
Thursday 10
Friday 9
Saturday 9
What is the critical value of chi-square with a
significant level of = 0.05?
a. 11.070
b. 12.592
c. 13.388
d. 15.033
21.
A public
opinion poll surveyed a simple random sample of voters. Respondents were
classified by gender and by voting preference—Republican, Democrat, or
Independent. The results follow.
Voting Preferences
Republican Democrat Independent
Row total
Male 200 150 50 400
Female 250 300 50 600
Column total 450 450 100 1000
If you conduct a chi-square test of independence, what
is the expected frequency count of male Independents?
a. 50
b. 60
c. 40
d. 30
22.
What
parametric test is equivalent to the nonparametric Spearman's rank test?
a. T-test of correlation coefficient
b. T-test of two sample means
c. T-test of one sample mean.
d. T-test of two sample proportions
23.
What is the
variable used to predict another variable called?
a. Independent variable
b. Dependent variable
c. Moderating variable
d. Intervening variable
24.
Michelle used
a sample of 50 U.S. cities to estimate the relationship between crime, or
annual property crimes per 100,000 persons, and income, or median income per
capita. Her estimated regression equation was crime = 428 - .01 income.
Assuming her model is statistically significant, if income decreases by $1,000,
we would predict that crime will
a. decrease by 1
b. increase by 10
c. decrease by 10
d. increase by 100
25.
In the least
squares equation, Y' = 12 + 25X the value of 25 indicates
a. the y- intercept
b. for each unit increase in 'x', y' increases by 25
c. for each unit increase in 'y', 'x' increases by 25
d. the residual of 'x' factor
26.
A test is
conducted in eight cities to see if giving away free transit system maps will
increase bus ridership. In a regression analysis, the dependent variable is the
increase in bus ridership in thousands of persons from the start of the test
until its conclusion. The independent variables are X1 = the number in
thousands of free maps distributed and X2 = a binary equal to 1, if the city
has free downtown parking and 0 otherwise. The estimated regression equation is
Y = 1.32+.0345X1-1.45X2. If the Y value for city 3 is 7.3, X1 = 140, and X2 = 0
the residual for city 3 in thousands is:
a. 6.34
b. 1.15
c. .57
d. 2.01
27.
The following
linear trend equation was developed for the annual sales of the Tractor
Manufacturing Company. Y' = 355 + 50t in thousands of dollars. How much are
sales increasing by?
a. $50,000 per year
b. $5,00 per month
c. $500,000 per year
d. $6,000 per year
28.
The time
series component that reflects variability over short, repetitive time periods
that last less than one year is called
a. long-term trend
b. cyclical variation
c. seasonal variation
d. irregular variation
29.
A research
company has been hired by a realty company to do an analysis of heating cost of
homes in the region. The realty company wanted to be able to predict the
heating cost of a typical single-family home. The realty company was constantly
being asked questions regarding heating costs by potential home buyers. It was
believed that these variables would impact heating costs (Y'): mean daily
outdoor temperature (X1), the number of inches of insulation (X2), and the age
in years of the furnace (X3). The multiple regression analysis produced the
following regression equation: Y' = 427.2 – 4.58X1 – 14.83X2 + 6.10X3. Which
statement is correct based on this analysis?
a. The age of the furnace has an indirect relationship
with heating costs.
b. There is an inverse relationship between outdoor
temperature and heating costs.
c. There is no real clear relationship between these variables.
d. There exists a direct relationship between inches of
insulation and heating costs.
30.
If we fit a
linear trend to data that are growing exponentially,
a. the fitted trend will be too high at the end
b. the forecasts, if extrapolated, will be too low
c. the forecasts, if extrapolated, will be too high
d. the fitted trend will be too low in the middle
