AP Stats Vocab Review

Used to compare the distribution of a quantitative variable for two groups. 

A variable that measures an outcome of a study. 

An important class of density curves that are symmetric, single-peaked, and bell-shaped.

If the right and left sides of a graph are approximately mirror images of each other. 

Gives every possible sample of a given size the same chance to be chosen. 

Let Y = the number of trials required to get the first success.

Describes the spread.

An individual value that falls outside the overall pattern of a distribution. 

Tells how many standard deviations a data point is from mean.

A variable that helps explain or influences changes in the other variable. 

Deliberately imposes some treatment on individuals to measure their responses. 

Minimum Q1 M Q3 Maximum 

Refers to the event “not A.”

Describes a graph of quantitative data with two clear peaks. 

When our P-value is less than the chosen significance level.

Study designs that involve making two observations on the same or two similar individuals.

Measures the average distance of the observations from their mean. 

The difference between an observed value and the value predicted by the regression line.  

Difference of third and first quartiles.

Can be described by the direction, form, and strength of the relationship. 

Family of distributions that take only positive values and are skewed to the right.

The probability that the events A and B occur can be found using P(A ∩ B) = P(A) ∙ P(B | A).

Has the general form: estimate ± margin of error.

A specific value of an explanatory variable (factor) in an experiment.

The mean of its sampling distribution is the true value of the parameter being estimated.

An inactive (fake) treatment. 

Experimental units that are human beings. 

The set of all possible outcomes of a chance process. 

Measures the direction and strength of the linear relationship between two variables.

Rule of thumb that all expected counts must be at least 5.

Used to display the sample space for a chance process that involves a sequence of outcomes.   

Gives the possible values of a random variable and their probabilities.

The arithmetic average.

Occurs when a selected individual cannot be contacted or refuses to cooperate.

The number such that half the observations are smaller and the other half are larger. 

Involves adding a constant, multiplying by a constant, or both.

The design of a statistical study systematically favors certain outcomes. 

All individuals in the chosen group are included in the sample. 

The imitation of chance behavior, based on a model that accurately reflects the situation. 

Maximum value minus the minimum value. 

A study that attempts to collect data from every individual in the population. 

When the standard deviation of a statistic is estimated from data.

Individuals to which treatments are applied.

The value of a statistic varies in repeated random sampling.

Occurrence of one event has no effect on the chance the other event will happen.

Denoted by A ∩ B, refers to the situation when both events occur at the same time.  

Also known as the "empirical rule." 

Null states the specified distribution of the categorical variable is correct.

A sample selected by taking the members of the population that are easiest to reach. 

An observation that if removed it would markedly change the result of the calculation.

The average squared distance of the observations in a data set from their mean. 

A number that describes some characteristic of a sample.

A graph of the five-number summary. 

Two events have no outcomes in common and so can never occur together. 

In a statistical study, the entire group of individuals about which we want information. 

A statement of “no difference.”

The most important influence on the answers given to a survey. 

There is no association between values of one variable and values of the other.

Occurs if H₀ is rejected when H₀ is true. 

Occurs when some members of the population are left out of the sampling frame.

The probability that the statistic would take a value as extreme as the one actually observed. 

Assesses the evidence provided by data about some claim concerning a population.

Expected number of trials required to get the first success.

Displays the distribution of a quantitative variable. 

A simple graph that shows each data value as a dot above its location on a number line. 

Groups of individuals that are similar in some way that might affect their responses. 

Is completely specified by two numbers, mean μ and standard deviation σ. 

Denoted by A ∪ B, consists of all outcomes in A,or B, or both.  

The amount by which y is predicted to change when x increases by one unit. 

The probability that one event happens given that another event has already happened.

When n is large, the sampling distribution of the sample mean is approximately Normal.

A number that describes some characteristic of the population.

Has mean 0 and standard deviation 1.