AP Stats Ch. 4 DEAD Words

Discrete Random Variable

Takes on countable outcomes with gaps in between them.

Continuous Random Variable

Takes on infinite outcomes without gaps between them.

Expected Value

A quantity equal to the average result of an experiment after a large number of trials.

Normal Distribution

A continuous probability distribution that is symmetric about its mean, with data concentrated near the center and tapering off toward the tails.

Empirical Rule

A shortcut for normal distributions (68, 95, 99.7) to estimate probabilities based on number of standard deviations from mean of a data set.

Binomial Distribution

The number of successes in a fixed number of independent trials, where each trial has exactly two outcomes (success or failure) and the same probability of success.

Large Counts Condition

A rule that checks whether a sample is large enough for the sampling distribution of a proportion to be approximately normal.

10% Condition

States that when sampling without replacement, the sample size must be no more than 10% of the population size. (This condition allows you to treat individual observations as approximately independent, even though they technically are not.)