Part C: Student Count by Status

In this part, we will count the number of students in each of the following groups: students who have been

accepted, students who actually enrolled in courses, current students, all former students, alumni, unretained

students, and students who were expelled.

We will now create a three new DataFrames to store student info for students in various categories. We will

then generate the desired counts.

Create a code cell to perform the following tasks:

$1.$ Create a DataFrame named enrolled. This DataFrame should be a subset of the accepted

DataFrame and should contain records only for those students who actually enrolled at the university.

Note that if a student enrolled, then they will have a record in the grades DataFrame. You should

use a filtering join to create this DataFrame.

$2.$ Create a DataFrame named current. This DataFrame should be a subset of the enrolled

DataFrame and should contain records only for those students who are currently enrolled at the

university. That is$,$ students who enrolled, but who do not appear in the alumni, unretained, or

expelled DataFrames. This will require multiple applications of a filtering join.

$3.$ Create a DataFrame named former. This DataFrame should contain records in enrolled that do not

appear in current. This will require a single filtering join.