Chapter 1.1 Flashcards
What is a data set?
A data set is a collection of facts and figures gathered for a specific study or purpose.
What are elements in a data set?
Elements in a data set are individual data points or observations, representing specific instances or units of measurement.
What are variables in the context of data sets?
Variables in data sets are characteristics or attributes that can be measured or observed, used for analysis and drawing conclusions.
What does a data set typically provide information about?
A data set typically provides information about a group of individual elements, which can be people, objects, events, or other entities.
How is the information about the elements in a data set described?
The information about the elements in a data set is usually described by one or more characteristics, and each of these characteristics is called a variable.
What is a quantitative variable?
A quantitative variable is a type of variable that represents numerical measurements or quantities and can be measured and expressed with numbers.
What is a qualitative variable?
A qualitative variable is a type of variable that represents characteristics or attributes that are not measured with numerical values, but rather with labels or categories.
What is a quantitative variable?
A quantitative variable is a variable that represents measurements with numerical values, typically indicating “how much” or “how many.”
Can you provide examples of quantitative variables?
Examples of quantitative variables include the actual selling price of a home, payment time of a bill, gasoline mileage of a car, and the 2016 payroll of a Major League Baseball team.
How are values of a quantitative variable typically represented?
Values of a quantitative variable are typically represented as numbers on the real number line.
What is a qualitative or categorical variable?
A qualitative or categorical variable is a variable that assigns elements to specific categories or labels without numerical values.
Can you provide examples of categorical variables?
Examples of categorical variables include a person’s gender, satisfaction with a product purchase, type of lot on which a home is built, and the color of a car
How is the data for a qualitative variable typically represented visually?
Data for a qualitative variable is often represented visually using charts or graphs, such as bar charts to display the distribution of categories
What is cross-sectional data?
Cross-sectional data are data collected at the same or approximately the same point in time, often representing different entities or individuals.
Can you provide an example of cross-sectional data?
An example of cross-sectional data is a bank analyzing last month’s cell phone bills for its employees because these bills represent cell phone costs for different employees in the same month.
What is time series data?
Time series data are data collected over different time periods, typically showing how a variable changes over time.
How are time series data typically represented visually?
Time series data is often represented visually using time series plots, where data points are plotted against their corresponding time index (e.g., years) on a horizontal scale.
How does a runs plot (time series plot) visually represent time series data?
A runs plot, such as Figure 1.3, displays each data point on the vertical scale against its corresponding time index (year) on the horizontal scale, illustrating changes or trends over time.
