Each Department's Share of the Students

Report how the student body splits across majors: return department (the department name, or Undeclared for the four students with no major), students (how many) and pct_of_total (that count as a percentage of all 30 students, rounded to 1 place). Compute the percentage with a window aggregate over the grouped result, SUM(COUNT(*)) OVER (), rather than a subquery. Sort by students descending, then department.

Expected result:

+------------------+----------+--------------+
| department       | students | pct_of_total |
+------------------+----------+--------------+
| Computer Science |        8 |         26.7 |
| Mathematics      |        5 |         16.7 |
| Biology          |        4 |         13.3 |
| Business         |        4 |         13.3 |
| English          |        4 |         13.3 |
| Undeclared       |        4 |         13.3 |
| Fine Arts        |        1 |          3.3 |
+------------------+----------+--------------+
7 rows

Hints4 available

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