problem-9.13
problem-9.13
After massaging the data, a glimpse at a contingency table shows
us that there appears to be some dependency between the variables. This
is borne out by the tiny p-value returned by chisq.test().
> aq = airquality[complete.cases(airquality),]
> attach(aq)
> te = cut(Temp, quantile(Temp))
> oz = cut(Ozone,quantile(Ozone))
> table(te,oz)
oz
te (1,18] (18,31] (31,62] (62,168]
(57,71] 15 9 3 0
(71,79] 10 10 7 1
(79,84.5] 4 6 11 5
(84.5,97] 0 0 6 22
> chisq.test(te,oz)
Pearson's Chi-squared test
data: te and oz
X-squared = 76.31, df = 9, p-value = 8.713e-13