Class Notes (806,888)
United States (312,248)
Statistics (75)
STAT 301 (55)

Measure of center, measure of spread, variance, standard deviation, interquartile range, boxplots

4 Pages
Unlock Document

Colorado State University
STAT 301
Brett Hunter

24 August A parameter is a value that pertains to the population Denoted by a Greek letter A statistic is a value that pertains to a sample Denoted by a Roman letter Numbers to describe data Measure of center For numeric variables: x Mean (μ for parameter, for statistic) Median Mode ≈ ≈ If histogram is symmetric, mean median mode If histogram is right skewed, mean > median > mode If histogram is left skewed, mean < median < mode For categorical variables: proportion of “successes” ̂ p π for parameter; , p, for statistic Still need to find a measure of spread, as just knowing where the center of the data is does not give us all the information we need. Measures of spread – provides a measure of uncertainty Range = max – min Deviation from sample mean How far a particular observation is from the sample mean X - x i Xi= the ith value from data set Measure of spread would need to include all deviations n ∑ (x −́ )0 Can’t take average of deviations, as i=1 i Say x = 3, x = 4, x = 6 1 2 3 3 ∑ xi = 3 + 4 + 6 i=1 Σ indicates a summation Variance Average squared deviation from the mean n 2 ∑ (x1−́x)2 S = i=1
More Less

Related notes for STAT 301

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.