Statistics Chapter 2 Terms Flashcards
What is a bar chart?
A graphic display device for discrete variables. Categories are represented by bars of equal width, the height of each corresponding to the number (or percentage) of cases in the category.
What are class intervals?
The categories used in the frequency distributions for interval-ratio variables.
What is cumulative frequency?
An optional column in a frequency distribution that displays the number of cases within an interval and all preceding intervals.
What is cumulative percentage?
An optional column in a frequency distribution that displays the percentage of cases within an interval and all preceding intervals.
What is a frequency distribution?
A table that displays the number of cases in each category of a variable.
What is a frequency polygon?
A graphic display device for interval-ratio variables. Class intervals are represented by dots placed over midpoints, the height of each corresponding to the number (or percentage) of cases in the interval. All dots are connected by straight lines. Also called a line chart.
What is a histogram?
A graphic display device for interval-ration variables. Class intervals are represented by contiguous bars of equal width (equal to the class limits), the height of each corresponding to the number (or percentage) of cases in the interval.
What is a line chart?
A graphic display device for interval-ratio variables. Class intervals are represented by dots placed over midpoints, the height of each corresponding to the number (or percentage) of cases in the interval. All dots are connected by straight lines. Also called a frequency polygon.
What is a midpoint?
The point exactly halfay between the upper and lower limits of a class interval.
What is a percentage?
The number of cases in a category of a variable divided by the number of cases in all categories of the variable, the entire quantity multiplied by 100.
What is percent change?
A statistic that expresses the magnitude of change in a variable from time 1 to time 2.
What is a pie chart?
A graphic display device especially for discrete variables with only a few categories. A circle (the pie) is divided into segments proportional in size to the percentage of cases in each category of the variable.
What is proportion?
The number of cases in one category of a variable divided by the number of cases in all categories of the variable.
What is rate?
The number of actual occurrences of some phenomenon or trait divided by the number of possible occurrences per some unit of time.
What is ratio?
The numver of cases in one category divided by the number of cases in some other category.
