1. RES 341 Final Exam
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1. Summary statistics computed from two independent samples are as follows: , ,
, , , and Construct a 95% confidence interval estimate for the difference between
the means of two normally distributed populations, where the unknown population
variances are assumed to not be equal. The upper confidence limit is
19.123.
28.212.
24.911.
5.788. 3
2. A study of 200 insomniacs paid for by the Serta Mattress Company found that
the average insomniac counted 350 sheep before falling asleep, with a standard
deviation of 120. An insomniac is a person who has difficulty falling asleep. Some
useful numbers might (0.89) (0.945) (0.89,199) (0.11,199) (0.055,199) 1.9302
Calculate an 89% confidence interval for the true mean number of sheep counted
by insomniacs.
A. 350±10.41
B. 350±13.56
C. 350±13.62
D. 350±16.38
3. Ceteris paribus, which is narrower, a 95% confidence interval with or a 99%
confidence interval with ?
A. The 95% confidence interval
B. The 99% confidence interval
C. They are the same width.
D. Need the margin of error to tell
4. When no point lies outside the control limits of a chart, we conclude that
variation in the process is

2. A. due to special causes and there is not enough evidence to infer that the
process is out of control.
B. due to special causes and there is enough evidence to infer that the process is
under control.
C. due to common cause and there is enough evidence to infer that the process
is out of control.
D. due to common cause and there is not enough evidence to infer that the
process is out of control.
5. When a change has occurred in the mean of the process distribution, the result
is referred to as
A. a level shift.
B. a trend.
C. instability.
D. a cycle.
6. What is the difference between probability sampling and simple random
sampling?
A. There is no difference.
B. In probability sampling each item has an identical chance of being chosen.
C. Probability sampling is a type of simple random sample.
D. Simple random sampling is a type of probability sampling.
7. When every member of a population has the chance of being selected based
on the probability, or frequency, of its representation in that population, you are
using which type of sampling?
A. Census sample
B. Convenience sample
C. Random sample
D. Quota sample
8. A recent study of breast cancer revealed that 13% of the women in the sample
used antibiotics more than 500 days in their lifetime. Further, 79% of these “heavy

3. antibiotics users” developed breast cancer. According to the American Cancer
Society, one in twelve women will develop breast cancer at some time in her life.
Of the numbers mentioned, which are parameters?
A. 13% and 79%
B. 79% and one in twelve
A. C.13% and one in twelve
C. 79% and 500 days
9. Which of the following statements is false?
A. A summary measure calculated from all items of interest is a parameter.
B. Statistical inference is the process of making a prediction based on only a
small piece of information.
C. A summary measure calculated from some of the items of interest is a statistic.
D. The main goal of descriptive statistics is to estimate characteristics of
populations.
10. Which of the following is NOT a reason one should have knowledge of
statistics?
A. To increase the amount of information available for use
B. To be able to mount an effective effort to change a government regulation that
negatively affects one’s business
C. To make future projections of one’s sales
D. To help interpret existing information
11. The collection and summarization of the socioeconomic and physical
characteristics of the employees of a particular firm is an example of
A. inferential statistics.
B. a statistic.
C. descriptive statistics.
D. a parameter.
12. Which of the following is NOT a potential source of survey error?

4. A. Standard error
B. Measurement error
C. Coverage error
D. Interviewer error
13. Which of the following would NOT be considered and potential pitfall for a
researcher?
A. Making conclusions about a large population from a small sample size
B. Unconscious bias on the part of the researcher
C. Attaching a low level of importance to outliers in a large population
D. Assuming causality based on observations
14. Which of the following is NOT an ethical concern for the statistical
researcher?
A. Protection of confidentiality
B. Informed consent
C. Use of sound methodology
D. Monetary compensation
15. A statistical researcher must be concerned about which of the following
ethical issues?
A. Monetary compensation
B. Protection of privacy
C. Conceal financial support
D. Inhumane treatment of animals
16. Textbook Price Number of Textbooks $25 to $35 2 35 to 45 16 45 to 55 5 55
to 65 7 65 to 75 20 Estimate the mean price of a textbook.
A. $554.00
B. $60.00
C. $11.08

5. D. $55.40
17. A multiple-choice test has 20 questions, and there are 4 choices for each
question.
A student comes to class with four different colored balls of identical shape and
size in her pocket. She has decided to draw one ball from her pocket per question
and allow the color of the ball to select the answer for each question. What type
of probability distribution can be used to figure out her chance of getting 10
questions right?
A. Hypergeometric distribution
B. Poisson distribution
C. Normal distribution
D. Binomial distribution
18. The local police department must write, on average, 5 tickets a day to keep
department revenues at budgeted levels. Suppose the number of tickets written
per day follows a Poisson distribution with a mean of 5.5 tickets per day. Interpret
the value of the mean.
A. The number of tickets written most often is 5.5 tickets per day
B. Half of the days have less than 5.5 tickets written and half of the days have
more than 5.5 tickets written
C. If we sampled all days, the arithmetic average or expected number of tickets
written would be 5.5 tickets per day.
D. The mean cannot be interpreted.
19. The Information Commons in the main library has 150 personal computers.
The probability that any one of them will require repair on a given day is 0.02. To
find the probability that exactly 25 of the computers will require repair, one would
use what type of probability distribution?
A. Binomial distribution
B. Poisson distribution
C. Normal distribution
D. Hypergeometric distribution

6. 20. The average qualifying speed for a championship NASCAR race is 145.65
mph and the standard deviation is 9.45 mph. Only drivers who obtain z-scores
greater than 1.2 will qualify for the race. If the speeds are normally distributed,
what minimum speed must be clocked to compete for the trophy?
A. 146.9 mph
B. 155.2 mph
C. 157.0 mph
D. 174.8 mph
21. The Big Red Arcade and Pizza Palace caters to young teens and sells tokens
to play arcade games for 25¢ each and slices of pizza for 50¢ each. The
distribution of sales of pizza slices per customer and sales of arcade tokens per
customer is below. # Slices of Pizza 0 1 2 3 4 5 Probability 0.05 0.10 0.20 0.30
0.15 0.20 # Arcade Games 0 1 2 3 4 5 Probability 0.01 0.04 0.15 0.20 0.25 0.35
What is the probability that revenues from pizza slice sales will be greater than
$1.00 per customer?
A. .95
B. .65
C. .85
D. .43
22. Which of these parameters associated with a binomial experiment will
produce a probability distribution with the smallest standard deviation; given n is
the same for each situation?
A.
B.
C.
D. (1- p) = 0.1.
23. When the only sources of variation in a production process are caused by
chance, the process is said to be
A. out of balance but under control.
B. out of control.

7. C. out of control but in balance.
D. under control.
24. The _________ states that the population correlation between two variables
is equal to zero or that the difference in the means of two groups in the population
is equal to zero.
A. directional hypothesis
B. nondirectional hypothesis
C. alternative hypothesis
D. null hypothesis
25. The process of picking the confounding characteristics and allocating them
across the groups being studied is called ___________.
A. matching
B. randomization
C. validity
D. experiments
26. Name the item that is NOT a recognized survey guideline.
A. pilot or beta test
B. ability to find friendly survey respondents
C. design
D. quality control
27. Which of the following is NOT a basic step in conducting a survey?
A. Create a research design
B. Secure financing for the survey
C. State the goals
D. Develop a budget
28. The average score for a class of 30 students was 75. The 20 male students in
the class averaged 70. The 10 female students in the class averaged

8. A. 85
B. 75
C. 80
D. 70
29. A child was born into the Doe family each year for five consecutive years.
What is the variance of the ages of the Doe children?
A. 1.4
B. 2.0
C. 4.6
D. 2.5
30. Identify the scale which has no meaningful zero.
A. nominal
B. interval
C. ordinal
D. ratio
31. Which measurement uses absolute values?
A. ratio correct
B. harmonic scale
C. ordinal scale
D. interval scale
32. Which of these measurement scales has a rank order associated with its use?
A. Ratio
B. Nominal
C. Ordinal
D. Likert

9. 33. The expected value of the sampling distribution of the sample mean equals
the population mean
A. when the population is normally distributed.
B. when the population is symmetric.
C. when the population size N > 30.
D. for all populations.
34. For a sample size of 1, the sampling distribution of the mean will be normally
distributed
A. regardless of the shape of the population.
B. only if the shape of the population is positively skewed.
C. only if the population values are larger than 30.
D. only if the population is normally distributed.
35. A random variable follows the student’s t distribution. The probability that it
will be positive
A. 1
B. 0.05
C. less than 0.50.
D. 0
36. A poll is planned to determine what proportion of all students favor an
increase in fees to support a new track and field stadium. A questionnaire will be
published and the first 1000 completed questionnaires will be analyzed. Which of
the following errors will be associated with the sample?
A. Sampling errors and errors due to selection bias
B. Sampling errors only
C. Errors due to interviewer bias and selection bias
D. Only non-sampling errors
37. Which of the following is NOT a characteristic of an ideal statistician?

10. A. Technically current (e.g. software)
B. Can deal with imperfect information
C. Communicates well (both written and oral)
D. Adapts answers to client desires
38. Which of the following is an example of statistical inference?
A. Counting the number of patients who file malpractice suits after being
discharged from hospitals in New York State.
B. Calculating the amount of fly spray needed for your orchard next season.
C. Calculating the mean number of fruit trees damaged by Mediterranean fruit
flies in California last year.
D. Calculating the mean age of patients discharged from hospitals in New York
State in 1997.
39. Which of the following statements is NOT true?
A. Scientific progress consists of continual refinement of theories through
hypothesis testing.
B. A statistical test may be significant yet have no practical importance.
C. Statistics is the science of collecting, organizing, analyzing, interpreting, and
presenting data.
D. Estimating parameters is an important aspect of descriptive statistics.
40. A __________ can be defined as a logically conjectured relationship between
two or more variables expressed in the form of a testable statement.
A. research design
B. theoretical framework
C. research problem
D. hypothesis
41. The manipulation of the independent variable is known as the ________.
A. experimental test

11. B. validity
C. randomization
D. treatment
42. Which of the following is NOT an ethical concern for the statistical
researcher?
A. Conceal financial support
B. Maintain data accuracy
C. Accurate reporting of procedures
D. Accepted procedures are followed
43. Which of the following is not an ethical concern for the statistical researcher?
A. Cite sources
B. Inhumane treatment of animals
C. Manipulation of data
D. Privacy of privacy
44. A supermarket has determined that daily demand for eggs has a bell-shaped
distribution, with a mean of 55 cartons and a standard deviation of six cartons. If
the supermarket begins each morning with a stock of 61 cartons of eggs,
approximately what percentage of days will there be a surplus of eggs?
A. ˜84%
B. ˜16%
C. ˜68%
D. ˜18%
45. Textbook PriceNumber of Textbooks
$25 to $352
35 to 4516
45 to 555
55 to 657

12. 65 to 7520
Estimate the standard deviation of the price of a textbook.
A. 729.00
B. 14.03
C. 196.78
D. 33.85
46. Which of these is NOT an acceptable type of survey question?
A. leading question
B. ranking questions
C. pictograms
D. Likert scale
47. Which of the following is a characteristic of every binomial distribution?
A. The outcome of a trial depends on the number of trials.
B. Each outcome is mutually exclusive.
C. The probability of success increases from trial to trial.
D. Each outcome is dependent on the previous outcome.
48. A popular restaurant recently asked 300 customers how may times per
month they ate steak for dinner. The results were used to build the following
probability distribution: x01234 or more P(x)0.050.100.200.300.15
The probability that a customer eats steak for dinner less than 3 times a month is
A. .15
B. .30
C. .50
D. .45
49. Trudy Jones recently completed her certification examination and learned
that her z-score was –2.5. The examining board also informed her that a failure to
pass would be all scores that were 1 or more standard deviations below the mean

13. and that those with scores higher than 2 standard deviations above the mean
would receive a special commendation award. Trudy can, therefore, conclude
that she
A. passed the exam, but no commendation award is forthcoming
B. passed the exam and will receive a special commendation award
C. needs more data to determine if she passed the exam
D. failed the exam
50. The use of the student’s t distribution requires which of the following
assumptions?
A. The sample is drawn from a positively skewed distribution
B. The population is normal
C. The population variance is known
D. The sample size is greater than 30
51. A random sample of 25 observations is selected from a normally distributed
population. The sample variance is 10. In the 95% confidence interval for the
population variance, the upper limit will be
A. 19.353
B. 6.097
C. 17.331
D. 17.110
52. In statistical process control, a Type I error occurs if we decide that the
process is
A. out of control when it is out of control.
B. out of control when it is under control.
C. under control when it is under control.
D. under control when it is out of control.
53. A sufficiently large coverage error will result in which of the following?

14. A. Statistics about the actual population rather than the target population
B. Non-response bias
C. Inability to perform inferential statistics
D. Probability sampling
54. Which one of the following is NOT part of the 5 step hypothesis testing
procedure?
A. Determine the level of significance desired.
B. State the null and the alternate hypotheses.
C. Determine the cost of the research.
D. Choose the appropriate statistical test.
55. A study of the scores on an in plant course in management principles and the
years of service of the employees enrolled in the course yielded the following
statistics: Test Scores: Years of Service: Of test scores and years of service,
which measure has the greater dispersion?
A. The short-run effects of those changes are always more beneficial to society
than are the long-run effects.
B. Years of service
C. It is impossible to tell.
D. Test scores
56. Which of the following cannot generate a Poisson distribution?
A. The number of defects in a new automobile
B. The number of customers arriving at an ATM in a minute
C. The number of goals in the World Cup soccer game
D. The number of people at a movie theatre on Friday evening
57. A study of 200 insomniacs paid for by the Serta Mattress Company found
that the average insomniac counted 350 sheep before falling asleep, with a
standard deviation of 120. An insomniac is a person who has difficulty falling
asleep. Some useful numbers might (0.89) (0.945) (0.89,199) (0.11,199)
(0.055,199) 1.9302 Out of the 200 insomniacs, 98 reported regularly watching

15. The Late Show with David Letterman before they began to count sheep.Calculate
the margin of error for a 78% confidence interval of the true proportion of
insomniacs who regularly watch David Letterman before counting sheep.
A. 0.136
B. 0.164
C. 0.056
D. 0.043
58. To tell if the standard deviation of a process has changed, the control charts
used are
A. R and S charts.
B. x bar and p charts.
C. p and R charts.
D. S and x bar charts.
59. When the results of a process are either defective or acceptable, the charts
used for SPC are called
A. control charts for attributes.
B. control charts for variables.
C. control charts for in control process.
D. control charts for out of control process.
60. A survey was mailed to a total of 400 students; 100 were randomly selected
from each of the freshman, sophomore, junior and senior classes last semester.
What sampling method was used?
1. Systematic sample
2. Simple random sample
3. Stratified sample
4. Cluster sample
61. Ten bolts were selected randomly from a production line and the diameter of
each was measured. Why do these diameters not have a binomial distribution?

16. 1. Diameter is a continuous random variable.
2. They do have a binomial distribution.
3. The diameters of the bolts are not independent of one another.
4. They have equal probability of success.
62. Kunlakarn has decided to invest in oil paintings as a hedge against inflation.
She is particularly interested in paintings by Picasso or Constable. Below is a
table of information about the value of paintings by these artists in differing states
of the Fine Art Market
1. There is no difference in the risk between the two collections.
2. Insufficient information to tell
3. Two Picassos and One Constable
4. One Picasso and Two Constables
63. The standard error of the sample mean is equal to 5 when If the sample size
increases by a factor of four, how will the standard error change?
1. It will double
2. It will quadruple
3. It will be cut to ¼ of 5
4. It will be cut in half
64. What does it mean to have 95% confidence in an interval estimate?
1. In repeated sampling, the population parameter would fall in the given interval
95% of the time.
2. In repeated sampling, 95% of the point estimates fall within the given interval.
3. In repeated sampling, 95% of the population observations fall within the given
interval.
4. In repeated sampling, 95% of the intervals would contain the population
parameter
RES 341 Final Exam
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