Ch. 2
The # of dots face up on the roll of a pair of dice
Discrete
Which type of data (categorical, discrete numerical, continuous numerical): Number of double faults in a randomly chosen tennis game at Wimbledon.
Discrete numerical
A ________ sample is taken from homogeneous subgroups of the target population
Stratified
T/F: The nominal scale of measurement is used to indicate the relative strength of a variable.
False - Nominal scale does not provide any meaningful numerical data.
T/F: The ratio scale of measurement is used for both qualitative and quantitative data
False - Ratio scale is used for quantitative data, but it does not make sense to use it for qualitative data.
T/F: The interval scale of measurement allows meaningful ratios to be constructed between the data values.
False - Ratios are only meaningful for the ratio scale, not the interval scale.
How do you determine the proportion of all 48 moviegoers who were under age 50?
# under age 50 / total = 36 / 48 = 0.75
A population may be treated as infinite when N is at least ______ that of n
20x
Data set
All values of all characteristics in a study
In sampling, what refers to over or underestimate a population parameter of interest?
Bias
Data that are generally expressed with words, rather than numbers, are known as ________ variables
Categorical
Which type of data (categorical, discrete numerical, continuous numerical): Nationality of a randomly chosen tennis player in the Wimbledon tennis tournament.
Categorical
Diners at a restaurant rate their food on a scale
Categorical or Qualitative
Data type (categorical, discrete numerical, or continuous numerical) and measurement level (nominal, ordinal, interval, ratio): What is your gender? (Male = 0, Female = 1)
Categorical; nominal
Use a sample or census to measure: The number of workers currently employed by Campbell Soup Company.
Census
Use a sample or census to measure: The total earnings of workers employed by Campbell Soup Company last year.
Census
Variable
Characteristic of interest
A __________ sample is taken from different geographical regions within a target population.
Cluster
Which sampling method was most likely to have been used (simple random, systematic, stratified, cluster)? A survey showed that 30 percent of U.S. businesses have fired an employee for inappropriate web surfing, such as gambling, watching porn, or shopping.
Cluster sample
Sample data can be characterized in different ways. Data that is collected about many subjects at the same point in time is known as ________ data.
Cross-sectional
Time series or cross-sectional: The number of skiers on the mountain on Christmas Day 2017 at each of the ski mountains owned by Vail Resorts.
Cross-sectional
T/F: Closing checkbook balances of 30 students on December 31 of this year is a time series variable
False
T/F: Focus group and sample are random sampling techniques
False
T/F: The nominal scale of measurement is used to measure quantitative variables
False
To assume that the scale uses interval measurements, what assumption is required?
Intervals are equal
Which sampling method was most likely to have been used (simple random, systematic, stratified, cluster)? In Spain, per capita consumption of cigarettes is 1,265 compared with 1,083 in the United States.
Likely based on sales, so no sample
A tabletop survey by a restaurant asked the question shown below. Were the food and beverage presentations appealing? Yes No. Choose an alternative response scale that would be more sensitive to differences in opinion.
Likert scale
Cross-sectional data Y/N: Quarterly sales for a computer company during the past three years.
No
Example of a nominal scale Y/N: The time it takes a worker to package a product for shipment.
No - ratio scale
What is a significant weakness of the ordinal scale?
No clear meaning to differences between the ranked values
Insurance companies are rated by several rating agencies. The Fitch 20-point scale is AAA, AA+, AA, AA-, A+, A, A-, BBB+, BBB, BBB-, BB+, BB, BB-, B+, B, B-, CCC+, CCC, CCC-, DD. What level of measurement does this scale use?
Ordinal
Is "How often do you use Excel?" nominal, ordinal, interval, ratio?
Ordinal
Is "how would you describe your level of skill in using Excel?" nominal, ordinal, interval, ratio?
Ordinal
_____________ data categorizes and ranks qualitative variables.
Ordinal
Parameter or statistic: The average price/earnings ratio for all 500 stocks in the S&P index.
Parameter
What includes all members of the group of interest?
Population
In order to create a sample representative of the population, the analyst should use a _________ sampling technique.
Random
Is "I spend ___________ hours a day using Excel." nominal, ordinal, interval, ratio?
Ratio
What type of survey will provide consistent responses from similar respondents over time?
Reliable
You want to know about the dating habits of college students, so you go to a dorm meeting and ask students how many dates they have had in the last year.
Response error
Use a sample or census to measure: The average price of a can of Campbell's Cream of Mushroom soup.
Sample
Which type of error is unavoidable when sampling from a population?
Sampling error
What is the group from which we take the sample?
Sampling frame
A tabletop survey by a restaurant asked the question shown below. Were the food and beverage presentations appealing? Yes No. Choose possible sources of bias in this type of survey.
Self-selection bias
Observation
Single value
a numerical summary of a sample
Statistic
Time series or cross-sectional: The annual compensation for the CEO of Coca-Cola Enterprises from 2010 to 2017.
Time series
Time series or cross-sectional: The weekly revenue for a Noodles & Company restaurant for the 52 weeks in 2017.
Time series
True or false: although non-random sampling techniques are considered less scientific than random techniques they are often used for expediency.
True
Sampling bias can best be reduced by
Utilizing random sampling
What type of survey provides information that the researcher wants?
Valid
Sample size is determined by _____________ in the population of interest and the desired ________ of the parameter being estimated
Variability; precision
Cross-sectional data Y/N: Last month's unemployment rate for various cities in Ohio.
Yes
Cross-sectional data Y/N: The hotel bill for each guest who stayed at a Holiday Inn on March 3rd.
Yes
Cross-sectional data Y/N: The total hours worked last week by each employee at a factory.
Yes
Example of a nominal scale Y/N: Social security numbers.
Yes
Is the number of pizzas ordered from Pizza Hut per day considered a variable?
Yes
The nominal scale of measurement is used to
categorize unranked data
Parameter or statistic: The average rate of return for 20 stocks recommended by a broker.
statistic
Parameter or statistic: The proportion of energy-related stocks in a random sample of 50 stocks.
statistic
A health maintenance organization is studying its daily office routine. It collects information on three variables: the number of patients who visit during a day, the patient's complaint, and the waiting time until each patient sees a doctor. Which variable is categorical?
the patient's complaint
Parameter or statistic: The proportion of all stocks in the S&P 500 index that had negative earnings last year.
Parameter
a numerical summary that describes a population
Parameter
How large would the university student population have to be in order to be regarded as effectively infinite if the sample size is 34 students?
34 x 20 = 680
A tabletop survey by a restaurant asked the question shown below. Were the food and beverage presentations appealing? Yes No. What kind of response scale has been used?
A binary response scale
Data type (categorical, discrete numerical, or continuous numerical) and measurement level (nominal, ordinal, interval, ratio):
Categorical; ordinal or interval
Which sampling method was most likely to have been used (simple random, systematic, stratified, cluster)? Surveyed doctors report that 59 percent of patients do not follow their prescribed treatment.
Cluster sample
The finishing times for running the 100m dash
Continuous
Is "Which version of Excel for Windows do you use?" nominal, ordinal, interval, ratio?
Nominal
A health maintenance organization is studying its daily office routine. It collects information on three variables: the number of patients who visit during a day, the patient's complaint, and the waiting time until each patient sees a doctor. Identify the two quantitative variables and state whether they are discrete or continuous.
Number of patients who visit during a day is discrete numerical; the waiting time until each patient sees a doctor is continuous
Data are quantities that represent or track the values taken by a variable over equally spaced periods
Time series data
T/F: A golfer's score relative to par and many Likert scales are examples of the interval scale of measurement
True
T/F: Focus groups and convenience are nonrandom sampling techniques
True
T/F: It can be difficult to ask a neutral/unbiased question in a survey
True
T/F: Stratified and cluster are random sampling techniques
True
True or false: A survey question might be discarded if too many responses are missing or flawed.
True
True or false: A survey question should avoid overlapping classes or unclear categories.
True
Example of a nominal scale Y/N: Designating males as 1 and females as 2 to compare gender performance on an aptitude test.
Yes
Example of a nominal scale Y/N: Specialty sandwich names at a fast food restaurant.
Yes
Which type of data (categorical, discrete numerical, continuous numerical): Age of a randomly chosen tennis player in the Wimbledon tennis tournament.
Continuous numerical
Time series or cross-sectional: The 2017 CEO compensation of the 500 largest U.S. companies.
Cross-sectional
Which sampling method was most likely to have been used (simple random, systematic, stratified, cluster)? The IRS reports that, based on a sample of individual taxpayers, 80% of those who failed to pay what they owed did so through honest errors or misinterpretation of the tax code.
Simple Random Sample
Data type (categorical, discrete numerical, or continuous numerical) and measurement level (nominal, ordinal, interval, ratio): About how many hours per week do you expect to work at an outside job this semester?
Continuous numerical; ratio
Data type (categorical, discrete numerical, or continuous numerical) and measurement level (nominal, ordinal, interval, ratio): What is your approximate undergraduate college GPA? (1.0 to 4.0)
Continuous numerical; ratio
You want to know how often people attend religious services, so you stand outside a particular church on Sunday and ask entering individuals how often they attend
Coverage error
You want to know how often people eat at McDonald's, so you stand outside a particular McDonald's and ask entering customers how often they eat at McDonald's
Coverage error
Data type (categorical, discrete numerical, or continuous numerical) and measurement level (nominal, ordinal, interval, ratio):
Discrete; ratio
T/F: The nominal scale of measurement is used to convert qualitative data to numerical data.
False - Even assigning a number to a category does not make it numerical.