chapter 1 Flashcards
individual
objects described by a set of data. individuals may be people, animals, and things.
variable
any characteristic of an individual. A variable can take different values for different individuals
categorical variable
variable that places an individual into one of several groups or categories
quantitive variable
variable that takes numerical values for which it make sense to find an average
distribution
tells what values a variable takes and how often it takes these values
marginal distribution
The distribution of one of the categorical variables in a two way table of counts among all individuals described by the table
conditional distribution
The values of one variable among individuals who have a specific value of another variable. there is a separate conditional distribution for each value of the other variable
Association
knowing the value of one variable helps predict the value of the other. If you knowing the value of one variable does not help predict the value of the other there is no association between the variables
SOCS
shape
outliers
center
spread
skewed left
tail goes to the left. left foot
skewed right
tail goes to the right. right foot
symmetric
A graph in which the right and left sides are approximately mirror images of each other
mean
the average
median
the middle
IQR
interquartile range
Q3-Q1
statistic
Number that describes some characteristic of a sample
Standard deviation
statistic that measures the typical distance of the values in a distribution from the mean. It is calculated by finding an average of the squared distances and then taking the square root in symbols
variance
“average” squared deviation of the observations in a data set from there mean. In symbols
