To compute the probability, we need to get first the total number of selected students in 12th grade. We have
![10+17+28+13=68](https://img.qammunity.org/2023/formulas/mathematics/college/z0xow0tu8ela7ag4nv619g21npq85vio9i.png)
Out of this number of 12th-grade students, 28 students prefer math. To get the probability, divide this number by the total number of students in 12th grade. We have
![P=(28)/(68)=0.412](https://img.qammunity.org/2023/formulas/mathematics/college/sqzic6x5oev17egwmqickryg4q1qe4d5cq.png)
Answer: 0.412