Percentage = (Score/Total Score) * 100
Percentage = (19/30) * 100
Percentage ≈ 63.33%
Now, let's assume the following grading scale:
A: 90-100%
B: 80-89%
C: 70-79%
D: 60-69%
F: Below 60%
Based on this scale, a score of 19 out of 30 corresponds to a grade of D or D+.