2.1.-2.2. Visual Description and Presentation of Data

ungrouped data

referring to individual data

frequency distribution

the arrangement of the statistical data that exhibits the frequency of the occurrence of the values of the variables; could be done in grouped data and ungrouped data

ungrouped frequency distribution

the arrangement of the statistical data that exhibits the frequency of the occurrence of every single value of the variables

bar graph

aka bar chart; length of the bar represents the amount, frequency, or percentage of the values falling into a category; allow you to compare percentages in the different categories;

pie graph/pie chart

a circle broken up into slices that represent categories; use to observe the portion of the whole that is in a particular category

line graph/line chart

capable of simultaneously showing values of two quantitative variables (y (vertical axis) and x (horizontal axis); consists of linear segments connecting points observed or measured for each variable

grouped frequency distribution

a summary table in which the data are arrange into numerically ordered classes

number of classes = 1 + 3.322 log n

determining the number of classes; where n = total number of data

width of interval = range/number of classes

determining the width of class interval; where range = highest value - lowest value

relative frequency distribution

describes the proportion or percentages of data values that fall within each category

relative frequencies

can be useful in comparing two groups of unequal size

cumulative frequency distribution

list the number of observations that are within or below each classes

histogram

a bar chart for grouped numerical data in which the frequencies or the percentages of each group of numerical data are presented as individual vertical bars; no gaps between the adjacent bars as there is in a bar chart of categorical data