Answer: 61.68%
Explanation:
To find the probability, we will divide the total number of wanted outcomes (students in 9th grade) by the total number of possible outcomes (all students).
Wanted / Total Possible = 9th Grade / All Students = 198 / 321 = 0.6168
Now, we can multiply this value and get an equivalent percentage if we need to.
0.6168 * 100 = 61.68%