STATISTICS CHAPTER 2

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. line segments are then drawn connecting the points.

raw data are data that is not

organized

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

pareto chart

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

pie chart

dot plot

placing each observation horizontally in increasing order and placing a dot above the observation each time it is observed

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

relative frequency

lists each category of data together with the relative frequency

relative frequency distribution

uniform distribution

frequency of each value of the variable is evenly spread out across the values of the variable

bell shaped distribution

highest frequency occurs in the middle and frequencies tail of to the left and right of the middle

in a relative frequency distribution, the relative frequencies add up to

1

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

histogram

constructed by labeling each category of data on either the horizontal or vertical axis and the frequency or relative frequency of the category on the other axis. rectangles of equal width are drawn for each category. the height of each rectangle represents the category's frequency or relative frequency

bar graph

classes

categories of data

the difference between consecutive lower class limits

class width

split stems

data appear rather bunched. rather than using one stem for the class of data 10-19 we could use two stems one for the 10-14 and the second for 15-19 interval

time series data

if the value of a variable is measured at different points in time, the eta are referred to as this

class width =

largest data value - smallest data value / number of classes

upper class limit

largest value within the class

stem ad leaf plot

represents quantitative data graphically. digits to the left of the rightmost digit to form the stem. each rightmost digit forms a leaf.

lower class limit

smallest value within the class

open ended

table is this if the first class has no lower class limit or th least class has no upper class limit

skewed left

tail to the left of the peak is longer than the tail to the right of the peak

skewed right

tail to the right of the peak is longer than the tail to the left of the peak