Statistics Chapter 3

percentile

each of the 100 equal groups into which a population can be divided according to the distribution of values of a particular variable.

Chebyshev's Theorem

he rule is often called Chebyshev's theorem, about the range of standard deviations around the mean, in statistics. The inequality has great utility because it can be applied to any probability distribution in which the mean and variance are defined.

Property of Median UPPER OR LOWER

median is used to find out if the data value falls in the upper or lower half of the distribution

Sample

sample is a set of data collected and/or selected from a statistical population by a defined procedure. ... Typically, the population is very large, making a census or a complete enumeration of all the values in the population is either impractical or impossible.

Symmetric

If the data are symmetric, they have about the same shape on either side of the middle. In other words, if you fold the histogram in half, it looks about the same on both sides

five-number summary

The five-number summary is a set of descriptive statistics that provide information about a dataset. It consists of the five most important sample percentiles: the sample minimum (smallest observation) the lower quartile or first quartile. the median (middle value)

Property of Mean OUTLIERS

The mean is affected greatly by extremely high of low values called outliers.

Property of Mean ALL VALUES

The mean is found by using all the values of the data set

Property of Mean UNIQUE

The mean of a data set is unique

Property of Median OPEN ENDED

The median can be used in frequency distributions

Property of Median OUTLIERS

The median is not affected very much by outliers

Property of Median CENTER

The median is used to find the center of middle value or the data set

Property of Midrange MIDPOINT

The midrange gives the midpoint of the range of the data set

Property of Midrange OUTLIERS

The midrange is affected by outliers

Property of Midrange EASY

The midrange is easy to compute

Property of Mode NOMINAL

The mode can be used for nominal and categorical variables

Property of Mode UNIQUE

The mode is not necessarily unique and may not even exist

Property of Mode EASIEST

The mode is the easiest average to find

Property of Mode TYPICAL

The mode is used to find the most typical case

Bimodal

a bimodal distribution is a continuous probability distribution with two different modes.

Left Skew

A "skewed left" distribution is one in which the tail is on the left side.

Right Skew

A "skewed right" distribution is one in which the tail is on the right side

boxplot

A box plot is a graphical rendition of statistical data based on the minimum, first quartile, median, third quartile, and maximum. The term "box plot" comes from the fact that the graph looks like a rectangle with lines extending from the top and bottom.

Population

Population is the entire pool from which a statistical sample is drawn. The information obtained from the sample allows statisticians to develop hypotheses about the larger population.

Property of Mean OPEN ENDED

To find the mean of a frequency distribution , there must not be an open-ended class

parameter

is a measurable characteristic of a population, such as a mean or a standard deviation

outlier

is a point which falls more than 1.5 times the interquartile range above the third quartile or below the first quartile.

decile

is any of the nine values that divide the sorted data into ten equal parts, so that each part represents 1/10 of the sample or population.

empirical rule

states that for a normal distribution, nearly all of the data will fall within three standard deviations of the mean.

coefficient of variable

the coefficient of variation (CV), also known as relative standard deviation (RSD), is a standardized measure of dispersion of a probability distribution or frequency distribution.