Res341 final exam | Mathematics homework help
1) 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. Convenience sample
B. Census sample
C. Random sample
D. Quota sample
2) 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 only
B. Sampling errors and errors due to selection bias
C. Errors due to interviewer bias and selection bias
D. Only non-sampling errors
3) 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 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. 79% and 500 days
B. 79% and one in twelve
C. 13% and 79%
D. 13% and one in twelve
4) Which of the following is NOT a characteristic of an ideal statistician?
A. Adapts answers to client desires
B. Can deal with imperfect information
C. Technically current (e.g. software)
D. Communicates well (both written and oral)
5) Which of the following is NOT a reason one should have knowledge of statistics?
A. To help interpret existing information
B. To be able to mount an effective effort to change a government regulation that negatively affects one’s business
C. To increase the amount of information available for use
D. To make future projections of one’s sales
6) Which of the following statements is NOT true?
A. Estimating parameters is an important aspect of descriptive statistics.
B. A statistical test may be significant yet have no practical importance.
C. Scientific progress consists of continual refinement of theories through hypothesis testing.
D. Statistics is the science of collecting, organizing, analyzing, interpreting, and presenting data.
7) If terms such as positive, negative, more than, and less than, are used, then these hypotheses are_________.
A. null hypotheses
B. nondirectional hypotheses
C. directional hypotheses
D. alternative hypotheses
8) A ___________ variable changes the relationship between the independent and dependent variables.
A. intervening
B. moderating
C. dependent
D. independent
9) Which of these is NOT an acceptable type of survey question?
A. Fill in the blank
B. Closed ended
C. Open ended
D. Prejudicial or biased questions
10) Name the item that is NOT a recognized survey guideline.
A. ability to find friendly survey respondents
B. design
C. pilot or beta test
D. quality control
11) Which of the following is NOT a potential source of survey error?
A. Nonresponse bias
B. Selection bias
C. Sampling error
D. Systemic error
12) Which of the following is NOT an ethical concern for the statistical researcher?
A. Accurate reporting of procedures
B. Maintain data accuracy
C. Accepted procedures are followed
D. Conceal financial support
13) Which of the following is NOT an ethical concern for the statistical researcher?
A. Informed consent
B. Use of sound methodology
C. Protection of confidentiality
D. Monetary compensation
14) Which of the following is not an ethical concern for the statistical researcher?
A. Manipulation of data
B. Inhumane treatment of animals
C. Privacy of privacy
D. Cite sources
15) 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. 2.0
B. 4.6
C. 1.4
D. 2.5
16) 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
A. 75
B. 80
C. 85
D. 70
17) 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: mean=100 variance = 225 Years of Service: mean=5 variance = 81 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. Test scores
C. Years of service
D. It is impossible to tell.
18) Identify the scale which has no meaningful zero.
A. interval
B. nominal
C. ordinal
D. ratio
19) Which measurement uses absolute values?
A. harmonic scale
B. ratio correct
C. ordinal scale
D. interval scale
20) Which of these measurement scales has a rank order associated with its use?
A. Nominal
B. Ratio
C. Ordinal
D. Likert
21) 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. Normal distribution
B. Binomial distribution
C. Poisson distribution
D. Hypergeometric distribution
22) Which of the following is a characteristic of every binomial distribution?
A. Each outcome is mutually exclusive.
B. Each outcome is dependent on the previous outcome.
C. The probability of success increases from trial to trial.
D. The outcome of a trial depends on the number of trials.
23) 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. Normal distribution
B. Hypergeometric distribution
C. Poisson distribution
D. Binomial distribution
24) 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. .85
B. .65
C. .43
D. .95
25) 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. 157.0 mph
B. 174.8 mph
C. 155.2 mph
D. 146.9 mph
26) 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 following table details the distribution of sales of pizza slices per customer and sales of arcade tokens per customer.
# Slices of Pizza 1 2 3 4 5
Probability 0.05 0.10 0.20 0.30 0.15 0.20
# Arcade Games 1 2 3 4 5
Probability 0.01 0.04 0.15 0.20 0.25 0.35
A. $2.42
B. $1.34
C. $2.60
D. $6.69
27) The standard error of the sample mean is equal to 5 when n=25. If the sample size increases by a factor of four, how will the standard error change?
A. It will be cut to ¼ of 5
B. It will quadruple
C. It will be cut in half
D. It will double
28) The use of the student’s t distribution requires which of the following assumptions?
A. The population is normal
B. The sample is drawn from a positively skewed distribution
C. The population variance is known
D. The sample size is greater than 30
29) The expected value of the sampling distribution of the sample mean equals the population mean
A. when the population size N > 30.
B. for all populations.
C. when the population is symmetric.
D. when the population is normally distributed.
30) 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. 17.331
B. 19.353
C. 6.097
D. 17.110
31) 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 be:
=NORMSINV(0.89) 1.2265
=NORMSINV(0.945) 1.5982
=TINV(0.89,199) 0.1385
=TINV(0.11,199) 1.6053
=TINV(0.055,199) 1.9302
Calculate an 89% confidence interval for the true mean number of sheep counted by insomniacs
A. 350±13.62
B. 350±13.56
C. 350±16.38
D. 350±10.41
32) Summary statistics computed from two independent samples are as follows: n1 = 50, x1 = 175, s1 = 18.5, n2 = 42, x2 = 158, and s2 = 32.4. 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
A. 24.911.
B. 28.212.
C. 5.788.
D. 19.123.
33) To tell if the standard deviation of a process has changed, the control charts used are
A. R and S charts.
B. p and R charts.
C. S and x bar charts.
D. x bar and p charts
34) In statistical process control, a Type I error occurs if we decide that the process is
A. under control when it is under control.
B. out of control when it is under control.
C. out of control when it is out of control.
D. under control when it is out of control.
35) When the only sources of variation in a production process are caused by chance, the process is said to be
A. under control.
B. out of control but in balance.
C. out of control.
D. out of balance but under control.
