Bus Stat Chap 2

Definitions from stat chap 2

frequency table

a grouping of qualitative data into mutually exclusive and collectively exhaustive classes showing the number of observations in each class.

distribution

a list that shows the possible values of a variable and a frequency or likelihood of occurrence. it includes values of the variable (points or categories) and a frequency or probability of occurrence of each values.

Frequency distribution

a list of values or categories of values of a variable along with actual frequency counts. also called a frequency table; a grouping of quantitative data into mutually exclusive and collectively exhaustive classes showing the number of observations in each class

probability distribution

a list of values or categories of values that gives the probability of occurrence for different outcomes of a process or experiment. also called a “relative frequency distribution”

observation

a data point collected during a scientific study; refers to one individual thing

frequency

the actual count of how many observations are in a category

relative frequency

a proportion; how often something happens divided by the sum of all outcomes; percent of occurrence; probability of the item/ category occurring

cumulative frequency

the actual number of observations that occur in a category and all preceding categories

cumulative relative frequency

the actual proportion of a particular item/ category and all preceding categories

mutually exclusive

two or more events cannot happen at the same time. categories of values of a variable do not overlap.

collectively exhaustive

all outcomes are included or accounted for. at least one of the outcomes must occur. all possibilities are covered. no other outcomes are possible. also referred to as “jointly exhaustive”

bar chart

a graph that shows qualitative classes on the horizontal axis and the class frequencies on the vertical axis. the class frequencies are proportional to the heights of the bars.

mode

the class of distribution with the highest frequency

pie chart

a chart that shows the proportion or percentage that each class represents of the total number of frequencies

histogram

a graph in which the classes are marked on the horizontal axis and the class frequencies on the vertical axis. the class frequencies are represented by the heights of the bars, and the bars are drawn adjacent to each other.