###Do age relate with DR
cor.test(age,duration_diabetes_min )

###Graph showing age versus DR
plot(age,duration_diabetes_min)

###load data
data("tusk")

### find the missing values
is.na(tusk)

### count the missing values
sum(is.na(tusk))

### Omit the missing values
na.omit(tusk)

### Remove missing values
mean(tusk $duration_diabetes, na.rm = TRUE)

### ANOVA TEST
mean(age)
mean(age[donor=male])
mean(age[donor=female])