Answer:
3/10 ; 0.3 ; 30%
Explanation:
The school that has 250 sixth graders, 225 seventh graders, and 275 eighth graders.
The probability of selecting a seventh grader is obtained by dividing the number of seventh graders in the school by the total number of students in the school.
The number of seventh graders is 225.
The total number of students in the school is:
250 + 225 + 275 = 750
Therefore, the probability of selecting a seventh grader is:
225/750 = 3/10
In decimal, it is 0.3
In percent, it is:
0.3 * 100 = 30%