Is each data set qualitative or quantitative?
The data are not numerical quantities. These are qualitative data.
Are the data numerical measurements?
Movie titles and jersey numbers are not numerical measurements, but a number of students is.
The data are numerical quantities. These are quantitative data.
The data are numerical but not measurements. They are qualitative data.
The kind of data you are working with determines the type of graph you use to display the data. A set of data that uses only one variable is univariate. A set of data that uses two variables is bivariate.
Is each data set univariate or bivariate?
There is only one variable, atomic weight. The data set is univariate.
There are two variables, edge length and volume. The data set is bivariate.
Does the data set involve one or two variables?
One variable means the data set is univariate. Two variables means the data set is bivariate.
Statisticians collect information about specific groups of objects or people. The entire group that you want information about is called a population. When a population is too large to survey, statisticians survey a part of it to find characteristics of the whole. The part that is surveyed is called a sample.
Three sampling methods are shown on the next page. When designing a survey, you should choose a sample that reflects the population.