Chapter 2 Flashcards
What is a data value?
An individual entry in a data set
pg. 30
What is a frequency?
The number of data values in a category
e.g. 3 people have brown hair the frequency is 3
pg. 30
What is a frequency distribution?
a table that with categories on the left and frequencies on the right
pg. 30
What does relative mean?
Use percents
pg. 31
What is a relative frequency distribution?
a table with categories on the left and frequency percents on the right
% found by dividing the frequency by the total # of data values
pg. 31
What is cumulative frequencey distribution?
a table with the frequencies being added to the together down the line
means that data is = to the category or less ;cumulative means ‘adding u
pg. 32
What is a histogram?
A bargraph with bars that touch, categories are horizontal and frequencies are vertical
pg. 33
What is a reative frequency histogram?
a bargraph with bars that touch using percetages
percentages are vertical axis
pg. 34
What is normal distribution?
When a graph has a single high point in the middle and low on the ends, symmetrical, and looks like a ‘bell curve’
pg. 35
What is classed frequently distribution?
a table with categories classes(range) on the left and frequency on the right
classes=group, e.g. 40-49
pg. 36
What are lower class limits?
the smaller of two numbers used to define each class
e.g. if the class is 40-49 the lower is 40
pg. 37
What are upper class limits?
the larger of the two numbers used to define each class
e.g. if the class is 40-49 the upper is 49
pg. 37
What is the class width?
the difference between two neighboring lower class limits
e.g. class 1: 40-49 class 2: 50-59; 50-40=10 class width is 10
pg. 38
What is the class boundaries?
halfway between an upper class limit and its neighboring lower class limit, to find the cut off between classes
upper(1)+lower(2)/2=boundaries
pg. 38
What is the class midpoint?
halfway between the lower class limit and upper class limit for each class, average within a class
lower+upper/2=midpoint
pg. 39
What is a frequency polygon?
a line segment using the class midpoint value on the horizontal axis with extra categories extended at beginning and end
find extra by adding class width to high/low midpoint
pg. 40
What is an ogive?
pronounced ‘oh-jive’
a line graph based on the cumulative frequency distribution with an extra category only at the start
extra for a strating point of 0
pg. 43
What is a pareto chart?
a bargraph based on frequency distribution but with qualitative data and should be in descending order according to frequently
qualitative=lables(not numbers), high to low
pg. 44
What is a dotplot?
horizontal line with categories and dots stacking for frequency
pg. 46
What is a stemplot/stem and leave plot?
a way to represent data with stems on the left usually the ten’s place and leaves on the right usually the one’s place
e.g. 0|2,3,5,7,=02,03,05,07
e.g. 1|1,2,3,3,=11,12,13,13
pg. 46
What is a time-series graph?
a line graph that tracks the value of some quantity through time, consists of pairs of data with time on the horizontal axis and value on the vertical
e.g. vaule=stock prices, time=months
pg. 47
