Shapes of Distribution

variables

characteristics (information about the cases)

Skewed Left

data is shifted toward the lower numbers.

Symmetry

distribution of data that have the same shape on both sides of the center.

maximum

highest number

median

middle number in order of the data

Cluster

several data points that lie close together within a small interval

mean < median

skewed left

mean > median

skewed right

mean = median = mode

symmetric

outilers

the numbers that lie away from others

Histogram

A graph that uses bars to show the frequency of equal ranges or groups of data.

mean

A measure of center in a set of numerical data, computed by adding the values in a list and then dividing by the number of values in the list.

Skewed Right

data is shifted toward the higher numbers.

Q3

top 25%

bimodal

two modes in the set of data

median

A measure of center in a set of numerical data - the value appearing at the center of a sorted version of the list - or the mean of the two central values if the list contains an even number of values.

Density curve

Area under = 1; above the x-axis

Gap

a larger space between sets of data values.

minimum

lowest numbr

range

Difference between the largest and smallest values that occur in a set of data.

cases

The subjects (or objects) of statistical examination.

mode

The value that occurs most frequently in a given data set.

Center, Shape and Spread

When you are asked to describe a set of data what should you always include?

Outlier

a number that is very different from the rest of the data set.

Q1

bottom 25%