FIXED AP Stats Vocab Review

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

A number that describes some characteristic of the population.

Expected number of trials required to get the first success.

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

Individuals to which treatments are applied.

The set of all possible outcomes of a chance process. 

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

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

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

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

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

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

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

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

Also known as the "empirical rule." 

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

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

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

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

An inactive (fake) treatment. 

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

Describes the spread.

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

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

The arithmetic average.

A statement of “no difference.”

Displays the distribution of a quantitative variable.

Deliberately imposes some treatment on individuals to measure their responses. 

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

The design of a statistical study systematically favors certain outcomes. 

Difference of third and first quartiles.

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

Describes a graph of quantitative data with two clear peaks.

A graph of the five-number summary. 

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

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

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

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

Maximum value minus the minimum value. 

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

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

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

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

Refers to the event “not A.”

A number that describes some characteristic of a sample.

Has mean 0 and standard deviation 1.

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

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

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

A variable that measures an outcome of a study. 

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

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

The value of a statistic varies in repeated random sampling.

There is no affect between the probability of one variable and the probability of the other.

Has the general form: estimate ± margin of error.

Occurs if H₀ is rejected when H₀ is true. 

Measures the average distance of the observations from their mean. 

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

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

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

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

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

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

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

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

Experimental units that are human beings. 

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

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

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

Minimum Q1 M Q3 Maximum 

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

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

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