Question on statistics

QUESTION 2 An ANOVA analysis is performed with six independent samples of equal size, testing as usual for a difference in the corresponding population means. The total degrees of freedom is 35. What is the degrees of freedom for the within sum of squares? Oa. 31 Ob. 5 O c. 30 Od. 6 QUESTION 3 We are conducting an ANOVA on 4 groups with the following sample sizes: /7 1 = 8, n2 = 12, n; = 6, n4 = 9. We wish to calculate a 95% confidence interval for the difference between / 1 and /3 (ie the difference in the means between groups 1 and 3). The formula for the confidence interval contains a critical value from a t-statistic, how many degrees of freedom does that t-statistic have? Oa. 31 Ob. 34 Oc. 12 Od. 14