Provide R codes and comments for Cross validationand Train & test data of Professors Salaries

Here's the following codes I have been using

```{r}

ibrary(carData)

library(MASS)

library(ISLR)

library(car)

library(leaps)

```

```{r}

Salaries1<-Salaries

str(Salaries1)

attach(Salaries1)

```

```{r}

#Summary variables

summary(Salaries1)

#1. Histogram Salaries

summary(Salaries1$salary)

par(mfrow=c(1,2))

hist(salary,col="pink",main="Professors Salary")

boxplot(salary)

```

Assessing Relations Regression

```{r}

#Correlation variables

pairs(Salaries1)

```

# Cross validation

```{r}

```

# Train & test data

```{r}

```