ai mi recorded the grade - level and instrument of everyone in the middle school school of rock…

ai mi recorded the grade - level and instrument of everyone in the middle school school of rock below.\nseventh grade students\n|instrument|# of students|\n|--|--|\n|guitar|7|\n|bass|12|\n|drums|6|\n|keyboard|11|\neighth grade students\n|instrument|# of students|\n|--|--|\n|guitar|9|\n|bass|15|\n|drums|4|\n|keyboard|14|\nbased on these results, express the probability that a seventh grader chosen at random will play the guitar as a fraction in simplest form.
Answer
Explanation:
Step1: Find total seventh - grade students
Add the number of students for each instrument in seventh grade. $7 + 12+6 + 11=36$.
Step2: Find number of seventh - grade guitar players
The number of seventh - grade guitar players is 7.
Step3: Calculate the probability
The probability $P$ that a seventh - grader chosen at random plays the guitar is the number of seventh - grade guitar players divided by the total number of seventh - grade students. So $P=\frac{7}{36}$.
Answer:
$\frac{7}{36}$