Quantitative Methods 2017

Parametric statistics

• Necessary to validate assumption • Example: test for deviation from normality • Remember: p-value >0.05 not enough

Normal P-P Plot of lnGTVrad

Normal

1.0

Mean = 3.7738 Std. Dev. = .83951 N = 85

15.0

0.8

10.0

0.6

Frequency

0.4

Expected Cum Prob

5.0

0.2

0.0

0.0

0.0

0.2

0.4

0.6

0.8

1.0

.00

1.00

2.00

3.00

4.00

5.00

6.00

Observed Cum Prob

lnGTVrad