# Daten laden
data <- read.csv("umfrage_daten.csv")

# Pakete
library(car)

# Angabe
data$auslandssemester2 <- recode(data$auslandssemester,"c(2,3)='2';else='1'")
data$auslandssemester2[data$auslandssemester==4] <- NA

(tab <- ftable(data$geschlecht~data$auslandssemester2))
(rtab <- round(tab,digits=2)/sum(ftable(tab)))
addmargins(round(tab,digits=4))
addmargins(round(rtab,digits=4))
round(14/22,digits=4)

# Loesung
# a)
1-0.6364
0.4545-0.2727
1-0.4545
0.1818/0.3636
0.5000-0.2727
0.5000-0.1818
addmargins(round(rtab,digits=4))

# b)
addmargins(round(rtab*44,digits=0))
24*22/44
20*22/44

(chisq <- round((10-12)^2/12 + (14-12)^2/12 + (12-10)^2/10 + (8-10)^2/10,digits=4))
(K <- round(sqrt(chisq/(chisq+44)),digits=4))
(Kstar <- round(K/sqrt(0.5),digits=4))

library(vcd)
assocstats(tab)

# c)
round((12/10)/(8/14),digits=4)

# d)
round(0.2727/0.5000,digits=4)