Data: https://cran.r-project.org/web/packages/Stat2Data/Stat2Data.pdf

6.31 Sleeping shrews. SleepingShrews Consider the shrew data of Example 6.7 where we are interested in whether and how heart rates differ between the three different phases of sleep. IE Shrew LSW DSW REM Mean A 14.0 11.7 15.7 13.8 B 25.8 21.1 21.5 22.8 C 20.8 19.7 18.3 19.6 D 19.0 18.2 17.1 18.1 E 26.0 23.2 22.5 23.9 F 20.4 20.7 28.9 20.0 Mean 21.0 19.1 19.0 19.7 a. Fit the two-way additive model Rate 2 Grand Average + Shrew + Phase + Error. b. Obtain a normal probability plot of residuals. Is there any indication from this plot that the normality condition is violated? c. Obtain a plot of residuals versus tted values. Is there any indication from the shape of this plot that the variation is not constant? Are there pronounced clusters? Is there an unmistakable curvature to the plot? Are there other issues