problem-7.29

problem-7.29  The data set implies that the population distribution is skewed and not normally distributed or symmetric. Thus t.test() and wilcox.test() are not appropriate. However, after a log transform, it appears that wilcox.test() will be.
> wilcox.test(log(commutes), conf.int=TRUE, conf.level=0.9)
...
 3.135 3.258
...
> exp(c(3.135,3.258))           # transform back
[1] 22.99 26.00
    
Or, that [23,26] is the confidence interval. The warning message is about the ties in the data. Notice that the sampling statistic is based on an assumption of a continuous distribution.