Statistical Sciences 2244A/B Chapter 1:
17 Feb 2020
School
Department
Professor
Document Summary
*sometimes the individuals represented in a data set are actually groups (ex countries, etc) Categorical variable places an individual into one of several groups or categories. Quantitative variable takes numerical values for which arithmetic operations make sense: values usually recorded in a unit of measurement (ex seconds, kilograms) Continuous variables can take any numerical value of an interval: ex plant height. Discrete variables can only take a limited, finite number of values: ex number of petals on a flower. Nominal variables are purely qualitative and unordered: ex flower colour. Ordinal variables can be ranked: ex likert scales, not true quantitative variables because the intervals between consecutive ranks are often not identical. Counts of a variable are also referred to as frequencies, and percents as relative frequencies. Histograms the distribution of a variable tells us what values the variable takes, and how often it takes these values the most common graph of the distribution of one quantitative variable is a histogram.
