Stochastik 1 Vorlesung 25

Komplette Vorlesung: https://youtu.be/Vd3y_6hpvTM?list=PLw1QLhW9bTaJkeMbqWvjB2itOsNveMvwH

https://youtu.be/Vd3y_6hpvTM?t=17m12s

library(MASS)
?survey
attach(survey)

NW.Hnd: span of non-writing hand.

Wr.Hnd: span (distance from tip of thumb to tip of little finger of spread hand) of writing hand, in centimetres.

W.Hnd: writing hand of student. (Factor, with levels “Left” and “Right”.)

Clap: ‘Clap your hands! Which hand is on top?’ (Factor, with levels “Right”, “Left”, “Neither”.)

plot(Wr.Hnd, NW.Hnd, main = 'Linear regression', 
     xlab = "Span of writing hand", ylab = "Span of non-writing hand")
abline(lm(Wr.Hnd~NW.Hnd), col = 'red', lwd=3)

https://youtu.be/Vd3y_6hpvTM

table(W.Hnd, Clap)

##        Clap
## W.Hnd   Left Neither Right
##   Left     9       5     4
##   Right   29      45   143

prop.table(table(W.Hnd, Clap))

##        Clap
## W.Hnd         Left    Neither      Right
##   Left  0.03829787 0.02127660 0.01702128
##   Right 0.12340426 0.19148936 0.60851064

barplot(prop.table(table(W.Hnd, Clap),2), legend.text = levels(W.Hnd), col = c('red', 'blue'))

Signifikanter Zusammenhang?

fisher.test(table(W.Hnd, Clap))

## 
##  Fisher's Exact Test for Count Data
## 
## data:  table(W.Hnd, Clap)
## p-value = 0.0001413
## alternative hypothesis: two.sided