4. (20 points)

```{r} # Please make sure you have the following two packages installed library(dplyr) library(magrittr) ```

Use `filter()` to find a subset of `Pima.tr` where `type` is `yes`. Name this subset `subset_yes`.

```{r} # Your code ```

In this subset, change the column name `bp` to `blood_pressure`, and `npreg` to `number_of_preg`. ```{r} # Your code ```

Use `arrange()` to sort `subset_yes` by `age` in decending order, and then `skin` in ascending order.

```{r} # Your code ```