Q&A Hero

Q: When data are qualitative, the bars should never be separated by gaps.

Q: Splitting the stems refers to assigning the same stem to two or more rows of the stem-and-leaf display.

Q: The stem-and-leaf display is advantageous because it allows us to actually see the measurements in the data set.

Q: A runs plot is a form of scatter plot.

Q: Beginning the vertical scale of a graph at a value different from zero can cause increases to look more dramatic.

Q: It is possible to create different interpretations of the same graphical display by simply using different captions.

Q: In the first step of setting up a Pareto chart, a frequency table should be constructed of the defects (or categories) in decreasing order of frequency.

Q: In a Pareto chart, the bar for the "Other" category should be placed to the far left of the chart.

Q: When constructing any graphical display that utilizes categorical data, classes that have frequencies of 5 percent or less are usually combined together into a single category.

Q: A frequency table includes row and column percentages.

Q: The sample cumulative distribution function is nondecreasing.

Q: When establishing the classes for a frequency table, it is generally agreed that the more classes you use the better your frequency table will be.

Q: When we wish to summarize the proportion (or fraction) of items in a class, we use the frequency distribution for each class.

Q: When looking at the shape of the distribution using a stem-and-leaf, a distribution is skewed to the right when the left tail is shorter than the right tail.

Q: A scatter plot can be used to identify outliers.

Q: Stem-and-leaf displays and dot plots are useful for detecting outliers.

Q: A bar chart is a graphic that can be used to depict qualitative data.

Q: The relative frequency is the frequency of a class divided by the total number of measurements.

Q: A stem-and-leaf display is a graphical portrayal of a data set that shows the data set's overall pattern of variation.

Q: Using the following data table of the average hours per week spent on Internet activities by 15- to 18-year-olds for the years 1999 to 2008, construct the runs plot and interpret.

Q: Looking at the runs plot of gasoline prices over the past 30 months, describe what it tells us about the price of gas during these 30 months.

Q: A study is being conducted on the effect of gas price on the number of miles driven in a given month. Residents in two cities, one on the East Coast and one on the West Coast, are randomly selected and asked to complete a questionnaire on the type of car they drive, the number of miles they live from work, the number of children under 18 in their household, their monthly income, and the number of miles they have driven over the past 30 days. List the factor(s).

Q: A study is being conducted on the effect of gas price on the number of miles driven in a given month. Residents in two cities, one on the East Coast and one on the West Coast, are randomly selected and asked to complete a questionnaire on the type of car they drive, the number of miles they live from work, the number of children under 18 in their household, their monthly income, and the number of miles they have driven over the past 30 days. Is this an experimental or observational study?

Q: A study is being conducted on the effect of gas price on the number of miles driven in a given month. Residents in two cities, one on the East Coast and one on the West Coast, are randomly selected and asked to complete a questionnaire on the type of car they drive, the number of miles they live from work, the number of children under 18 in their household, their monthly income, and the number of miles they have driven over the past 30 days. List the response variable(s).

Q: If we collect data on the number of wins the Dallas Cowboys earned each of the past 10 years, we have _____________ data. A. cross-sectional B. time series C. non-historical D. survey

Q: If we collect data on the number of wins each team in the NFL had during the 2011-12 season, we have _____________ data. A. cross-sectional B. time series C. non-historical D. survey

Q: Which of the following is not an example of unethical statistical practices? A. inappropriate interpretation of statistical results B. using graphs to make statistical inferences C. improper sampling D. descriptive measures that mislead the user E. None of the other answers is correct.

Q: One method of determining whether a sample being studied can be used to make statistical inferences about the population is to A. run a descriptive statistical analysis. B. calculate a proportion. C. create a cross-sectional data analysis. D. produce a runs plot.

Q: When the data being studied are gathered from a published source, this is referred to as a(n) _______________. A. existing data source B. observational data source C. experimental data source D. cross-sectional data source

Q: A data set provides information about some group of individual _____________. A. variables B. elements C. statistics D. measurements

Q: Data collected for a particular study are referred to as a data ____________. A. variable B. measurement C. set D. element

Q: The change in the daily price of a stock is what type of variable? A. qualitative B. ordinal C. random D. quantitative

Q: ___________ refers to describing the important aspects of a set of measurements. A. Cross-sectional analysis B. Runs plot C. Descriptive statistics D. Time series analysis

Q: A set of all elements we wish to study is called a ____________. A. sample B. process C. census D. population

Q: A(n) ____________ variable can have values that indicate into which of several categories of a population it belongs. A. qualitative B. quantitative C. ratio D. interval

Q: A sequence of operations that takes inputs and turns them into outputs is a ____________. A. process B. statistical inference C. runs plot D. random sampling

Q: A ____________ variable can have values that are numbers on the real number line. A. qualitative B. quantitative C. categorical D. nominative

Q: A ____________ is a subset of the units in a population. A. census B. process C. sample D. variable

Q: Statistical ____________ refers to using a sample of measurements and making generalizations about the important aspects of a population. A. sampling B. process C. analysis D. inference

Q: A ___________ is a display of individual measurements versus time. A. runs plot B. statistical analysis C. random sample D. measurement

Q: The process of assigning a value of a variable to each element in a data set is called ___________. A. sampling B. measurement C. experimental analysis D. observational analysis

Q: Any characteristic of an element is called a ____________. A. set B. process C. variable D. D)census

Q: Examining all population measurements is called a_____________. A. census B. frame C. sample D. variable

Q: Any characteristic of a population unit is a(n) A. measurement. B. sample. C. observation. D. variable.

Q: A person's telephone area code is an example of a(n) _____________ variable. A. nominative B. ordinal C. interval D. ratio

Q: A(n) _____________ variable is a qualitative variable such that there is no meaningful ordering or ranking of the categories. A. ratio B. ordinal C. nominative D. interval

Q: The number of miles a truck is driven before it is overhauled is an example of a(n) _____________ variable. A. nominative B. ordinal C. interval D. ratio

Q: College entrance exam scores, such as SAT scores, are an example of a(n) _____________ variable. A. ordinal B. ratio C. nominative D. interval

Q: ______________ is the science of using a sample to make generalizations about the important aspects of a population. A. Time series analysis B. Descriptive statistics C. Random sample D. Statistical inference

Q: __________ is a necessary component of a runs plot. A. Observation over time B. Qualitative variable C. Random sampling of the data D. Cross-sectional data

Q: An identification of police officers by rank would represent a(n) ____________ level of measurement. A. nominative B. ordinal C. interval D. ratio

Q: The weight of a chemical compound used in an experiment that is obtained using a well-adjusted scale represents a(n) _____________ level of measurement. A. nominative B. ordinal C. interval D. ratio

Q: Jersey numbers of soccer players is an example of a(n) ___________ variable. A. nominative B. ordinal C. interval D. ratio

Q: Temperature (in degrees Fahrenheit) is an example of a(n) __________ variable. A. nominative B. ordinal C. interval D. ratio

Q: The two types of quantitative variables are A. ordinal and ratio. B. interval and ordinal. C. nominative and ordinal. D. interval and ratio. E. nominative and interval.

Q: Measurements from a population are called A. elements. B. observations. C. variables. D. processes.

Q: Which of the following is a categorical variable? A. air temperature B. bank account balance C. daily sales in a store D. whether a person has a traffic violation E. value of company stock

Q: Which of the following is a quantitative variable? A. the manufacturer of a cell phone B. a person's gender C. mileage of a car D. whether a person is a college graduate E. whether a person has a charge account

Q: A ratio variable has the following characteristic. A. meaningful order B. inherently defined zero value C. categorical in nature D. predictable

Q: Data that are collected by an individual through personally planned experimentation or observation are _____________. A. secondary data B. quantitative data C. primary data D. variables

Q: _____________ is the difference between a numerical description of the population and the corresponding descriptor of the sample. A. Sampling error B. Non-observation error C. Observation error D. Non-response

Q: _____________ occurs when some population elements are excluded from the process of selecting the sample. A. Non-response B. Error of observation C. Undercoverage D. Sampling error

Q: A Yes or No question is _____________. A. dichotomous B. evaluative C. open-ended D. systematic

Q: Non-overlapping groups in random sampling of a population are called A. clusters. B. frames. C. strata. D. stages.

Q: A _____ is a list of all the units in a population. A. sample B. frame C. census D. variable

Q: Methods for obtaining a sample are called A. sample surveys. B. probability sampling. C. random sampling. D. sampling designs.

Q: Which of the following is a type of question used in survey research? A. dichotomous B. free response C. rating D. All of the other answers are correct.

Q: When we are choosing a random sample and we do not place chosen units back into the population, we are A. sampling with replacement. B. sampling without replacement. C. using a systematic sample. D. using a voluntary response sample.

Q: __________ consists of a set of concepts and techniques that are used to describe populations and samples. A. Traditional statistics B. Random sampling C. Data mining D. Time series analysis

Q: Transactional data are now used by businesses as part of A. survey analysis. B. big data. C. descriptive statistics. D. experimental studies.

Q: Which of the following is not a supervised learning technique in predictive analytics? A. linear regression B. factor analysis C. decision trees D. neural networks

Q: _________ uses traditional or newer graphics to present visual summaries of business information. A. Predictive analytics B. Data mining C. Association learning D. Descriptive analytics

Q: Which of the following is not a method of predictive analytics? A. factor detection B. outlier detection C. bullet graphs D. association learning

Q: ___________ sampling is where we know the chance that each element will be included in the sample, which allows us to make statistical inferences about the sample population. A. Convenience B. Voluntary C. Probability D. Judgment

Q: A ____________ is a set of assumptions about how sample data are selected and about the population from which the sample data are selected. A. random sampling B. statistical model C. descriptive statistics D. probability sampling

Q: A population that consists of all the customers who will use the drive-thru of the local fast food restaurant is called a(n) _____________. A. infinite population B. random sample population C. statistical population D. finite population

Q: Prescriptive analytics involve methods used to find anomalies, patterns, and associations in data sets with the purpose of predicting future outcomes.

Q: Business analytics uses methods that are not part of traditional statistics to look at big data.

Q: Judgment sampling occurs when a person who is extremely knowledgeable about the population under consideration selects the population element(s) that they feel is(are) most representative of the population.

Q: Judgment sampling is an example of convenience sampling.