Department

GeographyCourse Code

GGR270H1Professor

Damian DupuyStudy Guide

FinalThis

**preview**shows half of the first page. to view the full**2 pages of the document.**GGR 270 – Lecture 11 – November 24, 2010

P- Value

Decision to reject or fail to reject h0 is made by comparing the test statistic to a

critical value of z or t

But, different significance levels may lead to different conclusions

To avoid ambiguity, some researchers prefer to use a variable level of significance – P

value

Smallest value of a for which the h0 can be rejected

Actual risk of committing type 1 error

2 samples

In comparing 2 samples, if the sample means are significantly different, can

conclude they were drawn from different populations

2 sample difference of means test

Must examine difference in sample means

oIf sample difference is large, likely conclusion is the population means are

different

Need to know variances

oWe end up using 2 approaches according to whether we believe the variances

are equal or now

Both scenarios use T Statistic

Formulas

www.notesolution.com

###### You're Reading a Preview

Unlock to view full version