AP Stats Finals Flashcards
What is a population?
The entire collection of individuals or objects that make up a set
What is a sample?
A subset of the population selected for study
What are the two types of statistics?
Descriptive statistics: The branch of statistics that includes methods for organizing and summarizing data.
inferential statistics: The branch of statistics that involves generalizing from a sample to the population from which the sample was selected and assessing the reliability of such generalizations.
What is a variable?
Variable: A characteristic whose value may change from one observation to another.
What is data?
Data: A collection of observations on one or more variables.
What are the types of data sets?
Univariate data set: A data set consisting of observations on a single
characteristic is a univariate data set.
Categorical data set: A univariate data set is categorical (or qualitative) if the individual observations are categorical responses.
Numerical data set: A univariate data set is numerical (or quantitative) if eachobservation is a number.
What are the types of variables
Discrete Variable: A variable which is sorted into discrete categories
Discrete numerical variable: A numerical variable results in discrete data if the possible values of the variable correspond to isolated points on the number line.
Continuous numerical variable: A numerical variable results in continuous data if the set of possible values forms an entire interval on the number line.
What is a frequency distribution?
A chart which displays the frequencies for discrete variables
How do you calculate relative frequency?
Frequency/Number of Observations in the data set
How do you construct a bar chart?
Put all categories on 1 axis and frequency on the other. Draw bars for each category up to the frequency
How do you construct a dot plot and what does it show?
How to Construct
1. Draw a horizontal line and mark it with an appropriate measurement scale.
2. Locate each value in the data set along the measurement scale, and represent it by a dot. If there are two or more observations with the same value, stack the dots vertically.
What to Look for
● A representative or typical value in the data set.
● The extent to which the data values spread out.
What are the types of experiments
Observational
Observing a population and noting certain values of individuals observed to find trends.
Experimental
An experiment in which the investigator figures out how a response variable responds to a explanatory variable by manipulating it
The difference is that the observational study does not manually manipulate variables while the experimental does
What is a confounding variable?
Confounding variable: A variable that is related to both how the experimental groups were formed and the response variable of interest.
When can you and can you not draw conclusions about the population from a study?
Observational study with random participants: Yes
Observational study with convenience based sampling/volunteering: No
Experimental study with individuals which are volunteers or not randomly selected: No
Experimental study with individuals which are randomly selected from the population: yes
Experimental study with individuals not randomly assigned to experimental groups: No
When can you and can you not draw a cause and affect relationship from a study?
Observational study with random participants: No
Observational study with convenience based sampling/volunteering: No
Experimental study with volunteers or individuals which are not randomly selected from the population: Yes
Experimental study with individuals which are randomly selected from the population: Yes
Experimental study with individuals not randomly assigned to experimental groups: No
