UNIT 1 Flashcards
frequency
count/ how many
relative frequency
percent
marginal relative frequency
the percent count of occurrences in a single row in a data table compared to total
Joint relative frequency
the percent count of 2 categories together compared to total
Conditional relative frequency
the percent count of 1 category compared to a smaller category (not the total)
We have lots of ice cream flavors. what is the percent of chocolate compared to all the other flavors called
marginal relative frequency
We have lots of ice cream flavors. what is the percent of chocolate and strawberry compared to all the other flavors
joint relative frequency
some people like cones and some people like cups. What is the percent of people who like chocolate ice cream given they like cones
conditional relative frequency
what is it called when a variable explains or predicts another variable
explanatory variable and response variable
Quantitative Data
can measure
no ranges!
Categorical Data
values that are category names or groups
displayed using bar graphs
yes ranges
when you make a stem plot what should you not forget
TITILE and KEY
ex= 2/1 = 21
when you make a graph
DONT FORGET THE TITLE
How do you describe distributions
SOCS (shape, outliers, center, spread)
IQR formula
Q3-Q1
Outliers formula
1.5 IQR rule
low= x<Q1-1.5(IQR)
high= x>Q3+1.5IQR
SD method
low= x<mean-2sD .
high= x>mean+2sD
SOCS
1) shape
2) outliers
3) center (median or mean)
4) variability (range or sD or IQR)
Standard deviation process
1) do (x-mean)
2) (x-mean)^2
3) then add all up
4) divide by n-1then square root that
(n is the number of variables)
resistant to outliers
median and IQR
non-resistant to outliers
mean and SD and very affected by outliers
parameter
that describes entire population
statistic
that describes a sample taken from population
what is used to describe the center and the standard deviation
mean
interpret the median
about half the states have fewer than the median number of electoral votes and half of the states more than median number of electoral votes
if a distribution is strongly skewed to the right with no outliers its probably
mean>median
The scores on a stats test had a mean of 81 and a standard deviation of 9, One student was absent on the test day, and their score wasn’t included in the calculation. If these students score of 84 was added to the distribution of scores, what would happen to the mean and standard deviation
mean will increase and standard deviation will decrease
Is the individual of a data set a variable
NOPE
