English Test - Elementary

Percentage of Right Answers:
10 answers: 4%
13 answers: 4%
15 answers: 8%
17 answers; 20%
20 answers: 4%
21 answers: 12%
22 answers: 12%
23 answers: 8%
24 answers: 12%
25 answers: 16%

Mean = 20'2
Standard Deviation = 4'203