Data/Stats Chapter 1 Vocab

Individuals

objects that are described by data

Variable

Characteristics of Individuals

Categorical Variable

Places individuals into a group

Quantitative Variable

take numerical values to find an average

Distribution

what values a variable takes and often it takes these values

Marginal DIstribution

the distribution of values of that variable among individuals described in the table

Conditional Distribution

describes the values of that variable among individuals who have a specific value of another variable

marginal DIstribution equation?

row or column divided by total

conditional distribution

specific cell divided by the row or column total

skewed left

mean is LESS THAN the median

skewed right

mean is GREATER THAN the median

Resistant

a measure that is not affected by extreme observations

Resistant examples

median, IQR, Mode, Quartiles

Non resistant examples

mean, range, standard deviation

IQR

range of middle 50% of data

IQR = Q3-Q1

Rules for outliers

values that fall more than 1.5(IQR) above Q3 or below Q1

Five Number Summary

Min, Q1, Median, Q3, Max

Standard Deviation

measures the typical distance of the values in a distribution from the mean

use SD for spread when mean is also used

SD is greater than or equal to 0, SD = 0 with no spread

SD gets larger as data values are more spread out