## Dung observations
## Create a sample original data
data <- data.frame(Species=sample(c("W", "G", "R"), 200, replace=TRUE),
Age=sample(c("days", "weeks", "months"),200,replace=TRUE),
Termites=sample(c(0,1),200,replace=TRUE))
## Show what original data look like
head(data)
Species Age Termites
1 W months 0
2 R weeks 0
3 W weeks 0
4 G weeks 0
5 R months 1
6 W days 1
## Analyze each species
## Here we just tabulate Waterbuck as an example
data.w <- data[data$Species == "W",]
table.w <- table(data.w[,2:3])
## The results table looks like
table.w
Termites
Age 0 1
days 18 9
months 9 11
weeks 10 18
## Apply Chi-squared Test
chisq.test(table.w)
## Usually use Pearson's Chi-squared Test
## If your data are not suitable for the Pearson's Chi-squared Test, it
seems that R will tell you.
## H0 : All three age groups have same Termites attack percentage.
## H1 : All situations except H0.
-----
A R learner.
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