AP Statistics Vocabulary S

A fixed value used as a cutoff on what probability is or is not statistically significant.

When the effects of two different variables on a response variable cannot be told apart.

The amount of counts of a variable out of all counts, often expressed as a percent.

The range from Q1 to Q3.

The distribution of total values for categorical variables on a one-way or two-way table.

A group of experimental units that are similar and so are treated as one experimental unit.

The maximum minus the minimum.

The probability that a test will reject the Null when the Alternative is true.

When a distribution is even across the full range of values of the variable.

The probability that an event will occur given that another event has already occurred.

A sample selected by taking individuals that select themselves.

Individuals are monitored for measures of variables of interest but not influenced in response.

When the design of a study would consistently give an over or underestimate of the true value.

The four evenly sized sections of a set of ordered data.

An imitation of a chance behavior that uses a model that accurately represents the situation.

The occurrence of one event or the other, or both.

The number of standard deviations to be added/subtracted from the test statistic (z* or t*)

The fraction of the variation that can be explained by the least-squares regression line (r²).

The variable that may predict the changes in another variable.

When neither the researchers nor the subjects know which treatments were assigned to groups.

A graph of quantitative data with two clear peaks.

When a group of the population does not get accurate representation in a sample.

The total value to be added/subtracted from the test statistic to find the interval max/min.

The set of all possible outcomes of a chance process.

The sum of the values of the observations divided by the number of observations.

A model that describes the overall pattern of a distribution.

A procedure using a sample statistic to make a decision about the validity of a claim.

The # of standard deviations an observation falls from the center of a Normal distribution.

A family of distributions that always take on positive values and are skewed right.

The occurrence of two events at the same time.

A variable that takes on a finite number of values (usually no decimals).

The distribution of a random variable of continuing trials until a certain number of successes.

The claim that we actually believe to be true that we are trying to find evidence for.

A variable that takes on an infinite number of values.

The distribution of a random variable with the number of trials set in advance.

A graph that shows bars that have ranges for counts of a continuous variable.

When the right and left sides of a distribution are mirror images of each other.

The proportion of observations that are lower than a particular observation.

The middle number (resistant to outliers).

A sample where each individual was randomly chosen from the population.

A study where researchers deliberately impose treatment on the individuals.

A non-symmetric distribution that has a distinct tail.

The science of data.

Explains the linear relationship between two quantitative variables, from -1 to 1.

The (inaccurate) use of a regression line to estimate outside the range of the given data.

Making conclusions about a larger population based on sample data.

The distribution of many samples.

The number of individuals of a sample found in each category in response to a survey.

In experiments, when all variables except for the explanatory variable must be kept the same.

A range of plausible values for a parameter, based on a statistic.

The response value a Least Squares Regression Line would expect for a given explanatory value.

An event that rarely would have happened just by chance.

The probability that an event does NOT happen.

A sample by putting individuals into population-like groups and randomly choosing one group.

When it is not possible for two event to occur simultaneously.

The probability that the statistic would have taken on a value given the Null hypothesis true.

The proportion of a chance process will approach a single value as you do more trials.

A graph of the five-number summary.

The difference between an observed value and its predicted/expected value.

A number from a sample used to estimate some characteristic of a population.

__% of all such samples would produce a range of values that would capture the true value.

The typical or common distance observations are away from the mean.

A common form of blocking in comparing two different treatments, often on the same sample.

Occurs when we reject the Null hypothesis when it was actually true.

The most common number.

An individual that falls well outside the pattern of data.

Minumum, Q1, Median, Q3, and Maximum values of a data set.

An inactive (fake) treatment for which some subjects may actually respond.

The standard deviation of a significance test or confidence interval.

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

The claim that we do not believe to be true that we are trying to find evidence against.

A family of distributions like the Normal curve expect with more variability in the samples.

A number that describes some characteristic of a population.

Decisions based through a process of chance.

The smallest collection of individuals to which a treatment is to be applied.

When knowing the value of one variable helps to predict the value of another.

A study that attempts to survey every individual of the population.

The entire group of individuals which we are interested in knowing something about.

The number of individuals that would be found in each category if the Null hypothesis is true.

When randomly selected individuals cannot be contacted or refuse to participate.