APEX AP Stats Lesson 1.2.4 Study: Intro to Frequency Data and Their Graphs Studyguide

Frequency Table

shows both distinct values and how often they appear; shows the counts of each data value

Class

a range of data to make it easier to examine data

Class Width

the difference between the upper and lower class limits of back-to-back classes; size or length of that interval

Class Boundaries

dividing points between classes in a frequency distribution/histogram; separate each class

Class Interval

specific range of values in a specific class in a frequency distribution

Histogram

breaks the range into groups and displays the count of the observations in each interval

Relative Frequency

the fraction of the total observations

Relative Frequency Histogram

uses the relative frequency of data points to make a graph instead of raw frequency/data

Midpoint (in a histogram)

represents the center value of each class interval or bar

Cumulative Frequency

running total of frequencies in a frequency distribution, showcases the sum of a value and all preceding values

Cumulative Relative Frequency

proportion of observations in a data set that fall at or below a specific value/range of values

Cumulative Frequency Graph

aka cumulative frequency plot; line graph plotting cumulative frequency on the y axis and class boundaries/interval midpoints on the x axis

Categorical Data

set of labels telling us which class an individual falls into

Numerical Data

can be measured on a number scale; counts or measurements

Bar Graph

shows counts or frequencies of categorical data

Stem-and-leaf plots

useful if you want to compare the distributions of a variable for two different samples or populations

Frequency shown on the y axis

categories/data topic on the x axis

Cumulative Frequency in the last interval

always = the total amount of observations

Cumulative Relative Frequency in the last interval

always = 1

Y axis for Cumulative Frequency Plot

cumulative frequency

Y axis for Cumulative Relative Frequency Plot

cumulative relative frequency