Answer
Gender: since we could not reject the null hypothesis, it is not necessary to perform the Tukey’s test.
Age: $µ_{18-34}\neµ_{55~and~older}=µ_{35-54}$
Work Step by Step
With the results from item (b) still available:
Select Stat -> ANOVA -> General Linear Model -> Comparisons
In Response select Serum Cholesterol (mg/dL). In Type of comparison select Pairwise. In Method select Tukey. In Choose terms for comparisons select Age.
Click OK.
