> fail <- factor(c(2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1,
                   1, 2, 1, 1, 1, 1, 1),
           levels = 1:2, labels = c("no", "yes"))

> temperature <- c(53, 57, 58, 63, 66, 67, 67, 67, 68, 69, 70, 70,
                   70, 70, 72, 73, 75, 75, 76, 76, 78, 79, 81)
> cdplot(fail ~ temperature)

> which(temperature == 67)
6 7 8

> which(temperature == 67 & fail == 1)
integer(0)

> which(temperature == 67 & fail == "no")
[1] 6 7 8

prop.table(table(temperature, fail),1)