is the science of conducting studies to collect, organize, summarize, analyze, and draw conclusions
statistics
variable
data
quantitative variables
is a characteristic or attribute that can assume different values
discrete
continuous
are the values that variables can assume
variables
qualitatives
is a collection of date values
data set
random variables
continous varibales
have values that are determined by chance
discrete variables
can be placed into distinct categories according to some characteristics or attribute
qualitative variables
are numerical in nature and can be ordered or ranked
assume values that can be counted
continuous variables
random, variables
can assume all values between any two specific values
nominal
classifies data into mutually exclusive (non overlapping), exhausting categories in which no order or ranking can be imposed on the data
ordinal
classicfies data into categories that can be ranked: however, precise differences between the ranks do not exist
continuous variable
random variable
ranks data, and precise differences between units of measure do exist, however, there is no meaningful zero
interval
ratio
posses all the characteristics of interval measurement, and there exists a true zero
consists of the collection, organization, summarization, and presentation of data
descriptive statistic
inferential statics
consists of generalizing from samples to populations, performing hypothesis testing, determine relationships among variables, and making predictions.
inferential statistics
descriptive statistics
is the chance of an even occurring
probability
population
sample
consists of all subjects that are being studied
is a group of subjects selected from a population
are selected using chance methods or random methods
random samples
systematic samples
data sets
by numbering each subject of the populations and then selecting every nth number
by dividing the population into groups according to some characteristics that is important to the study, the sampling from each group
stratified samples
cluster samples
by using intact groups called clusters
thee researcher mercy observes what is happening or what has happened in the past and tries to draw conclusions based ion these observations
observational study
experimental study
the researcher manipulates one of the variables and tries to determine how the manipulation influences the variables
observation study
data collected in original form is called
raw data
frequency distribution
categorial frequency distribution
is the organization of raw data in table form, using classes and frequencies
frequencies distribution
nominal or ordinal level data that can be places in categories is organized
categorical frequency distribution
are used when the range of the data is large
grouped frequency distribution
lower and upper class limits
class boundaries
the smallest and largest possible data values in class are the
lower and upper limits
is a graph that displays the data by using vertical bars of various heights to represent the frequencies of the classes
histogram
is a graph that displays the data by using lines that connects points plotted for the frequencies at the class midpoints. the frequencies are represented by the heights of the points
frequency polygon
class midpoints
is a graph that represents the cumulative frequencies for the classes in a frequency distribution
ogive
if proportions are used instead of frequencies, the graph are called
relative frequency graphs
a statistical graph in which each data value is plotted as a point above the horizontal axis
dotplot
a data plot that uses part of a data value as the stem and part of the data value as the leaf to form groups or classes
stem and leaf plot
dot plot