Summary Statistics: Graphs That Enlighten or Deceive Notes

Statistics ~ Graphs that enlighten or deceive

,Frequency distribution:shows how data are partitioned among several
categories by listing the categories along w/the
number frequency) of data values in each ofthem
->
Helps us to understand the nature ofthe distribution of a data set
->
Helpful in organizing and summarizing data


Lower class limits:smallest numbers thatcan belong to each of the
differentclasses

Upper class limits:largest numbers
class boundaries:numbers used to separate the classes two gaps
created by class limits
class midpoints:values in the middle of the classes

class width:difference between 2 consecutive lower class limits in
a
frequency distribution


class width = (max.data) -
(min.datal ->
round up
for move
A ofclasses
convenient #


Distribution:Each class
Relative
frequency/Percent frequency
frequency is replaced
by a relative

frequency/percentage
Relative
frequency for a class frequency
-
for a class
Sum of all frequencies
↓

a sum oft he percentages freq. For a class 100%
x
must be very close to 100% sum of all frequencies