Shapiro-Wilks normality test performed on standardized residuals. | ||||
---|---|---|---|---|
 | W | P |  |  |
Without outlier | 0.984 | 0.06 | Â | Â |
With outlier | 0.960 | 0.0001 | Â | Â |
T test to see if mean of standardized residuals was not zero. | ||||
 | Mean | T | df | P |
Without outlier | -0.003 | -0.03 | 158 | 0.97 |
With outlier | -0.003 | -0.03 | 159 | 0.97 |
Bartlett's test to see if the standardized residuals, divided into four groups by their corresponding fitted values, lacked constant variances. | ||||
 | K2 | Df | P |  |
Without outlier | 4.43 | 3 | 0.22 | Â |
With outlier | 15.02 | 3 | 0.002 | Â |