section 2.2 Flashcards
distribution
of each variable which is information that tells us what values the variable takes on and how often
what are the guidelines for grouping data into classes are ?
- small number of classes to be effective , but enough to show differences
- each observation must belong to only one class
- whenever feasible classes should have same width
frequency
which is the number of observations that fall into a class (count )
frequency distribution
a listing of all classes of the data and their frequencies
relative frequency
which is the ratio of the frequency of a class to the total number of observationsr
relative frequency distribution
a listing of all lasses and their relative frequencies
frequency histogram
is a graph that display s the assess on the horizontal axis and the frequencies on the veritcal axis
relative frequency histogram
is the same as a frequency histogram , except it uses relative frequencies for the vertical axis and the bar heights
pie chart
is a disk (circle ) divided into pie shaped pieces proportional to the relative freque3ncies
bar graph
the width of the bars is arbitrary and the bars are not connected can show frequency or relative frequency
Pareto chart
is a specific type of bar graph where the classes are reordered so that the bras are in size order
center
where is the middle of the graph and the highest point
spread
how are the parts of the graph spread out from each other
shape
what shape does the graph have
symmetry
graph can be split in half with two mirrors images parts , almost equal amount on both sides
