Stats Key Terms 2

The average of a data set: (x1 + x2 …+ Xn)/n

the middle value of a set of numbers

the most frequently occurring number found in a set of numbers.

• The minimum.

• Q1 (the first quartile, or the 25% mark).

• The median.

• Q3 (the third quartile, or the 75% mark).

• The maximum.

the value under which 25% of data points are found when they are arranged in increasing order

the value under which 75% of data points are found when arranged in increasing order

measures the spread of the middle half of your data: IQR = Upper Quartile – Lower Quartile = Q­3 – Q­1

A measure of the amount of variation or dispersion of a set of values:

σ=√((∑〖(x_i-μ)〗^2 )/N)

measures variability from the average or mean: (∑〖(x_i-x)〗^2 )/ (n - 1)

An observation that lies an abnormal distance from other values in a random sample from a population.

a graphical rendition of statistical data based on the minimum, first quartile, median, third quartile, and maximum

visually groups the number of data points in a data set based on the value of each point

a type of simple histogram-like chart used in statistics for relatively small data sets where values fall into a number of discrete bins

a graph that shows the frequency of numerical data using rectangles

uses the same information as a frequency histogram but compares each class interval to the total number of items

the data is graphed in groups of 1 sec times

describes the number of peaks in a dataset

a probability distribution which has a single peak

Distribution has two peaks

a probability distribution with more than one mode

the long tail is on the right side of the distribution. The higher side is on the left side

the long tail is on the left side of the distribution. The higher side is on the right side

two sides of the distribution are a mirror image of each other

a type of probability distribution in which all outcomes are equally likely

a type of table in a matrix format that displays the (multivariate) frequency distribution of the variables.

The pictorial representation of data, in the form of vertical or horizontal rectangular bars, where the length of bars is proportional to the measure of data

a form of bar chart that shows the composition and comparison of a few variables, either relative or absolute, over time

used to display two categorical variables

a type of bar graph that represents the proportional contribution of individual data points in comparison to a total

used to compare two or more categories by using vertical or horizontal bars

a visual display comparing the levels (the possible values) of one categorical variable by means of a quantitative variable