problem-8.35

problem-8.35  The data is not independent among the samples as there are only 205 parents and 930 children represented. Treating it as though the pairs are independently drawn, we can use a paired t-test to get
> attach(galton)
> t.test(child,parent,paired=TRUE)

        Paired t-test

data:  child and parent
t = -2.966, df = 929, p-value = 0.003089
alternative hypothesis: true difference in means is not equal to 0
...
> detach(galton)
    
The small p-value indicates a difference in the means. The confidence interval suggests that it is between 0.07 inches and 0.37 inches.