Statistics Section 2.1 - 2.4

raw data

data that is not organized

frequency distribution

lists the number of occurrences for each category of data

relative frequency

the proportion or percent of observations within a category and is found using the formula (answer)=frequency/sum of all frequencies

relative frequency distribution

lists the relative frequency of each category of data

bar graph

constructed by labeling each category of data on a horizontal axis and the frequency or relative frequency of the category on the vertical axis; a rectangle of equal width is equal to the category's frequency or relative frequency

Pareto chart

bar graph where the bars are drawn in decreasing order of frequency or relative frequency

side-by-side bar graph

compares two data sets

pie chart

a circle divided into sectors where each sector represents a category of data and the area of each sector is proportional to the frequency of the category

histogram

constructed by drawing rectangles for each class of data whose height is the frequency or relative frequency of the class and the width of each rectangle should be the same and they should touch each other

classes

categories of data are created for continuous data using intervals of numbers called

lower class limit

the smallest value within the class

upper class limit

the largest value within the class

class width

the difference between consecutive lower class limits

stem

consists of the leading digits in a graph

leaf

the rightmost digits of a graph

class midpoint

found by adding a class's lower class limit and upper class limit and dividing the result by 2

frequency polygon

drawn by plotting a point above each class midpoint on a horizontal axis at a height equal to the frequency of the class, after the points for each class are plotted, draw straight lines between consecutive points

cumulative frequency distribution

displays the aggregate frequency of the category

cumulative relative frequency distribution

displays the aggregate proportion of observations less than or equal to the category

ogive

graph that represents the cumulative frequency or cumulative relative frequency for the class

time series data

the value of a variable is measured at different points in time

time series plot

obtained by plotting the time in which a variable is measured on the horizontal axis and the corresponding value of the variable on the vertical axis