Statistics: Measures of Central Tendency and Dispersion

These flashcards cover key vocabulary related to statistics, specifically focusing on measures of central tendency, dispersion, and data interpretation.

Mean

The mean, or arithmetic average, is computed by adding all the values and dividing by the number of observations.

Median

The median is the middle value of data when arranged in ascending order; it separates the data into two equal halves.

Mode

The mode is the most frequently occurring value in a dataset.

Outlier

An outlier is an unusual data value that differs significantly from other observations in a dataset.

Resistant Statistic

A statistic is considered resistant if it is not substantially affected by extreme values.

Standard Deviation

The standard deviation is a measure of the amount of variation or dispersion in a set of values.

Variance

Variance is the square of the standard deviation, representing the degree of spread in the dataset.

Interquartile Range (IQR)

The IQR is the range of the middle 50% of the data, calculated as Q3 - Q1.

Z-score

The z-score indicates how many standard deviations a data value is from the mean.

Empirical Rule

States that for a bell-shaped distribution, about 68% of the data falls within one standard deviation of the mean, 95% within two, and 99.7% within three.

Chebyshev's Inequality

For any data set, at least 1 - (1/k^2) of the observations lie within k standard deviations from the mean for k > 1.

Five-Number Summary

The five-number summary consists of the minimum, first quartile (Q1), median (Q2), third quartile (Q3), and maximum of a dataset.

Boxplot

A boxplot is a graphic representation of the five-number summary, showing the distribution of data and identifying outliers.