Answer
$M=5.67$
$median=6$
$mode=3$
Work Step by Step
The mean:
$M=\frac{∑X}{N}=\frac{3+6+7+3+9+8+3+7+5}{9}=\frac{51}{9}=5.67$
Scores in ascending order: $3~~3~~3~~5~~6~~7~~7~~8~~9$
Since there are 9 scores ($N=9$), the median is the 5th score in ascending order:
$median=6$
Frequencies:
Score $3$: $3$
Score $7$: $2$
Other scores: $1$
$mode=3$
