Lesson 8.4-8.5

range

difference of the highest score minus lowest score

less than culmulative frequency (<CF)

found by adding the frequency of the class and the frequency of the lower classes

greater than culmulative frequency (>CF)

found by adding the frequency of the class and the frequency of the upper classes

class

grouping or category

upper limit

highest number in a class interval

5 to 15

ideal number of classes

mean

intersection of the less than ogive and greater than ogive

ogive

line graph where the culmulative frequency of each class is plotted against the corresponding class boundary

frequency polygon

line graph where the frequency of each class is plotted against the corresponding class mark

lower limit

lowest number in a class interval

class mark (CM)

middle value in a class

class boundaries

often described as true limits because these are more precise expressions of class limits

class frequency (f)

rate at which something is repeated over a particular period of time or in a given sample, determined by counting the tally

class interval (i)

size of each class, defined by range over desired number of classes, the result of which is rounded to the nearest integer

frequency distribution table

tabular presentation of data for both grouped and ungrouped numerical information

median, mode

two measures of central tendency that are easy to find in stem-and-leaf plots

lower boundary (LB)

0.5 less than the lower limit of a class

upper boundary (UB)

0.5 more than the upper limit of a class

stem-and-leaf plot

a process of organizing ungrouped data

histogram

bar-like representation of a frequency distribution, where the height of each bar corresponds to the frequency of the class and the width corresponds to the interval of the class