Review Slides Flashcards
Statistics
A collection of methods for collecting, displaying, analyzing and drawing conclusions from data.
Descriptive Statistics
the branch of statistics that involves organizing, displaying and describing data.
Inferential Statistics
the branch of statistics that involves drawing conclusions about a population based on info contained in a sample taken from that population.
Population
any specific collection of objects of interest.
Sample
any subset of the population.
Census
A sample that consists of the whole population.
Measurement
a number or attribute computed for each member of a population or sample.
Sample data
The collective measurements of sample elements.
Parameter
number that summarizes some aspect of the population as a whole.
Statistic
number computed from the sample data.
Individuals
the individual units of observation (members of a population or a sample)
variable
any characteristic of an individual.
Distribution
tells us what values the variable takes, and how often it takes these values.
Qualitative data/variables
measurements for which there is no natural numerical scale, but which consists of attributes or other non-numerical characteristics.
Quantitative variables/data
measurements for which there is a numerical scale.
Categorical Variable
codes whether each one in a set of observations is in a particular category.
Nominal variable
assigns numerical labels to qualitative variables that represent different categories that cannot be ranked.
Ordinal variable
assigns numerical labels to qualitative variables that represent different categories that can be ranked.
data list
explicit listing of all the individual measurements made on a sample.
data frequency table
table listing each distinct value (x) and its frequency.
Frequency of a value x
is the number of times it appears in the data set.
Sturges’ Rule
the desirable number of classes = k, the closest integer to:
1+3.3log(n)
Sample size
The number of individuals in a sample
Absolute class frequency (or class frequency)
the number of measurements in the data set that are in the class