Means Tests Hypothesis Testing Assumptions Testing (Normality)

Normality Tests Many Statistical Tests require normal data You must verify normality with a test

Testing for Normality How do we test for normality? Compute the linear correlation coefficient between the sample data and normal scores

H 0 : (null hypothesis): data normally distributed H a : (alternative hypothesis): Data not normal Hypothesis Testing Normality Test

Hypothesis Testing Normality Test Test Statistic P-value Critical Value (Alpha ɑ) = ??

How to we use p? Compare p-value from test to specified significance level (alpha, α=0.05) If the p-value is less than or equal to α=0.05, reject the null hypothesis, Otherwise, do not reject (fail to) the null hypothesis

Hypothesis Testing Normality Test P-value: <0.01 Alpha (ɑ) = 0.05 Since p is < ɑ Reject the null hypothesis

Since we reject the null hypothesis H 0 : (null hypothesis): data normally distributed We accept the alternative hypothesis H a : (alternative hypothesis): Data not normal …and determine that data are not normally distributed Hypothesis Testing Normality Test