ECO 250 CH. 1 Test Review

The American Statistical Association describes eight general topic areas and specifies important ethical considerations under each topic. One area is "Professionalism". Professionalism points out the need for competence, judgment, diligence, self-respect, and worthiness of the respect of other people. Which of the following adheres to upholding the ethical guidelines for statistical practice? a)Use only statistical methodologies suitable to the data and to obtaining valid results. For example, address the multiple potentially confounding factors in observational studies and use due caution in drawing causal inferences. b)Guard against the possibility that a predisposition (bias) by investigators or data providers might predetermine the analytic result. c)Account for all data considered in a study and explain the sample(s) actually used. All of these are valid elements of professionalism, and are maintaining ethical guidelines.

All of these are valid elements of professionalism, and are maintaining ethical guidelines.

The number of observations in a complete data set having 20 elements and 3 variables is: a)20-3 b)20+3 c)20*3 d)20.

d)20. The number of elements is equal to the number of observations. There are 20 elements in the data set: therefore, there are 20 observations.

Cross-sectional data

Data collected at the same or approximately the same point in time.

The population of countries (n = 60) with the top GDPs in 2014 is shown above. Assume for the purposes of this problem that the mean and median GDP of this population are unknown. In reality, they are ($51,195, $44,600). A random sample of 10 countries (GDPs) was selected from this unknown population. What range would the sample mean most likely fall into? a)$50K — $59.9K b)$40K — $49.9K c)$30K — $39.9K d)$60K — $69.9K

a)$50K — $59.9K

What is the principal difference between time series data and cross-sectional data? a)Cross-sectional data are limited to an approximate window of time, while time series data are collected over several time periods. b)Time series data seeks only to capture data within a snapshot in time. c)Cross-sectional data looks at only a particular "cross-section" of the population. d)Time series data and cross-sectional data are concerned with different sized samples.

a)Cross-sectional data are limited to an approximate window of time, while time series data are collected over several time periods.

Which of these is a continuous and quantitative variable? a)The time it takes to grill a steak b)The pairs of shoes in your closet c)The number keys on a piano d)The number of internet sales in Cyber on Monday

a)The time it takes to grill a steak

The summaries of data, which may be tabular, graphical, or numerical, are referred to as: a)descriptive statistics. b)qualitative statistics. c)quantitative statistics. d)inferential statistics.

a)descriptive statistics.

Statistical Inference: a)is the process of drawing conclusions about the population based on the evidence taken from the sample. b)is the same as a census. c)refers to the process of drawing conclusions about the sample based on the characteristics of the population. d)is the same as a description using tabular and graphical statistics.

a)is the process of drawing conclusions about the population based on the evidence taken from the sample.

In a sample of 200 students in a university, 40, or 20%, are Communications majors. Based on the above information, the school's paper reported that "an estimated 20% of all the students at the university are Communications majors." This report is an example of: a)statistical inference. b)a population. c)a sample. d)an experiment.

a)statistical inference.

All of the following are examples of observational studies except: a)the behavior of Walmart shoppers after they are given a $20 gift card from the store. b)an online survey to record your satisfaction with a company's service. c)the number of cars running a stop sign in a residential area during rush hour. d)a Gallup poll measuring the approval rating of the President.

a)the behavior of Walmart shoppers after they are given a $20 gift card from the store. All of the following are examples of observational studies except the behavior of Walmart shoppers after they are given a $20 gift card from the store. Behaviors will vary because a treatment is introduced, which will elicit a response. Since a control (the gift card) is present, it cannot be called an observational study

The collection of all elements of interest in a particular study is: a)the population of interest. b)statistical inference. c)the sample of interest. d)descriptive statistics.

a)the population of interest.

Data mining is the analysis step of the "knowledge discovery in databases" process. It has become an emerging field in today's business world because: a)the sheer amount of useful data has grown exponentially. b)research and development has become too costly. c)normal statistical analysis is too complicated. d)other types of analysis are ineffective.

a)the sheer amount of useful data has grown exponentially.

A time series is a sequence of data points, typically consisting of successive measurements made over a time interval. Examples of the time series include all except: a)the volume of shares traded today in the stock market. b)a stock's opening price for each month. c)Ocean tides. d)point differential against opponents for a football team this year.

a)the volume of shares traded today in the stock market. Tides are continuous and measured over the course of time

Examples of quantitative data include all of the following except: a)your zip code. b)your weight rounded to the nearest gram. c)the temperature outside to the nearest degree. d)the number of pairs of shoes in your closet.

a)your zip code.

What is the principal connection between a sample and a population? a)A population cannot be accurately described by any sample. b)A random sample drawn from a population seeks to describe the characteristics of that population. c)A population describes all sample data. d)Small samples can be drawn to describe small populations.

b)A random sample drawn from a population seeks to describe the characteristics of that population.

Data obtained from a nominal scale: a)must rank and order the data. b)can be either numeric or nonnumeric. c)must be alphabetic. d)must be numeric.

b)can be either numeric or nonnumeric.

The major applications of data mining have been made by companies with a strong _____ focus. a)electronic design b)consumer c)human resource d)research and development

b)consumer The major applications of data mining have been made by companies with a strong consumer focus, such as retail businesses, financial organizations, and communications companies

In a sample of 1600 registered voters, 912, or 57%, approve of the way the President is doing his job. The 57% approval rating is an example of: a)statistical inference. b)descriptive statistics. c)a sample. d)a population.

b)descriptive statistics.

The owner of a factory regularly requests a graphical summary of all employees' salaries. The graphical summary of salaries is an example of: a)statistical inference. b)descriptive statistics. c)a sample. d)an experiment.

b)descriptive statistics.

The sample size: a)can be larger or smaller than the population size. b)is always smaller than the population size. c)can be larger than the population size. d)is always equal to the population size.

b)is always smaller than the population size.

Data collected through a survey attached to this month's pay stub: a)will have no data acquisition error. b)is considered an observational study because no control is imposed. c)is experimental because the control is the time of month it was administered. d)will be useless because not everyone receives the survey.

b)is considered an observational study because no control is imposed.

Some hotels ask their guests to rate the hotel's services as excellent, very good, good, and poor. This is an example of the: a)nominal scale. b)ordinal scale. c)interval scale. d)ratio scale.

b)ordinal scale. Some hotels ask their guests to rate the hotel's services as excellent, very good, good, and poor. This is an example of the ordinal scale. Ordinal data is data in which the order or rank is meaningful

In data mining, statistical models play an important role in developing _____. a)businesses b)predictive models c)human resources d)financial organizations

b)predictive models

Anyone who wants to use the data and statistical analysis as aids to decision making must be aware of the time and cost issues. If important data are not readily available, it would be best to: a)borrow another company's data. b)use a cross-sectional data set. c)conduct a times series analysis. d)do nothing at all due to cost.

b)use a cross-sectional data set. If important data are not readily available, it would be best to use a cross-sectional data set. This option allows for data to be taken in a short time window. This would also be best in terms of cost, and advantageous because existing data could be used

The largest experimental statistical study ever conducted is believed to be for:​ a)Flu vaccine b)Cholera. c)Polio. d)Diptheria

c)Polio. The largest experimental statistical study ever conducted is believed to be the 1954 Public Health Service experiment for the Salk polio vaccine. Nearly 2 million children in grades 1, 2, and 3 were selected from throughout the United States

Examples of categorical data include all of the following except: a)90,210 (Beverly Hills). b)extra large. c)blonde. d)228 lbs.

d)228 lbs.

In a random sample of 200 items, 5 items were defective. An estimate of the percentage of defective items in the population is: a)10% b)5% c)2.5% d)20%

c)2.5%

Examples of cross-sectional data include all except a)comparison of mpg data gathered on all 2015 cross-over SUVs b)comparison of performance of all telecommunications stocks today c)comparison of sales output of all 10 salespeople in the Western Sales Region for the 3rd quarter d)comparison of five different variables for the WTO nations on January 1st

c)comparison of sales output of all 10 salespeople in the Western Sales Region for the 3rd quarter This sales data is examined over a 3-month time interval

The Department of Transportation of a city has noted that on the average there are 17 accidents per day. The average number of accidents is an example of: a)a sample. b)statistical inference. c)descriptive statistics. d)a population.

c)descriptive statistics.

The Department of Homeland Security has noted that on average 1120 suspicious vehicles are stopped and searched each day in the United States. This number is used to estimate the number of cars stopped in an average yearly period. The average number of cars stopped is not an example of: a)a population. b)a sample. c)descriptive statistics. d)statistical inference.

c)descriptive statistics. The average number of cars stopped is not an example of a descriptive statistic. The statistic mentioned is gathered daily and used to describe the population of the United States

The entities on which data are collected are: a)samples. b)populations. c)elements. d)observations.

c)elements.

An experiment is conducted to study the effects of a new blood pressure medicine on subjects. A random sample of 60 people are placed into three groups of 20 according to their age (young, middle-aged, and senior). Each group of 20 people are randomly assigned to two treatment groups (new medicine and placebo). How many total treatment groups are there? a)4 b)2 c)1 d)6

d)6

Which of the following is not a type of data acquisition errors? a)Data being used before the source is properly vetted. b)A subject's answers may be transcribed incorrectly. c)The person asking a survey question may place undo emphasis on one of the answer choices. d)A particularly extreme value is verified, and is still included in the data set.

d)A particularly extreme value is verified, and is still included in the data set. A particularly extreme value is verified, and is still included in the data set. Although the data is an outlier, it should not be included in the data set, it is not ignored because it is properly verified

The American Statistical Association describes eight general topic areas and specifies important ethical considerations under each topic. One area is "Responsibilities to Research Subjects". It describes the requirements for protecting the interests of human and animal subjects of research not only during data collection but also in the analysis, interpretation, and publication of results of the findings. An example of this would include: a)avoiding or minimizing the use of deception. Where it is necessary and provides significant knowledge-as in some psychological, sociological, and other research-ensure prior independent ethical review of the protocol and continued monitoring of the research. b)avoiding excessive risk to research subjects and excessive imposition on their time and privacy. c)know about and adhere to appropriate animal welfare guidelines in research involving animals. Ensure that a competent understanding of the subject matter is combined with credible statistical validity. d)All of these practices adheres to the ASA's policy.

d)All of these practices adheres to the ASA's policy.

A company wants to enhance the benefits for its yearly healthcare package offering. It observes the set of employees who smoke on their break times at 10 a.m., 12 p.m., and 2 p.m. It records the number of cigarettes smoked by each individual. This is an example of: a)an experiment with no placebo. b)a randomized study. c)a controlled experiment. d)an observational study.

d)an observational study.

Statistical studies in which researchers do not control variables of interest are: a)placebo studies. b)completely randomized studies. c)experimental studies. d)observational studies.

d)observational studies. Statistical studies in which researchers do not control variables of interest are observational studies. An observational study simply gathers information on phenomena without imposing any control over the elements being observed

Data mining deals with methods for developing useful decision-making information from large databases. It performs all actions except the: a)warehousing of data. b)collection of useful data. c)extraction of predictive information. d)reselling of the packaged data.

d)reselling of the packaged data.