Question

question samir recorded the grade - level and instrument of everyone in the middle school of rock below. seventh grade students instrument # of students guitar bass drums keyboard 6 4 6 7 eighth grade students instrument # of students guitar bass drums keyboard 9 9 9 10 based on these results, express the probability that a seventh grader chosen at random will play an instrument other than drums as a fraction in simplest form.

Explanation:

Step1: Calculate total number of seventh - graders

Sum the number of students for each instrument in seventh grade: $7 + 6+4 + 6=23$.

Step2: Calculate number of seventh - graders who play an instrument other than drums

Sum the number of students playing keyboard, bass, and guitar: $7 + 4+6 = 17$.

Step3: Calculate the probability

The probability $P$ that a seventh - grader chosen at random plays an instrument other than drums is the number of students playing an instrument other than drums divided by the total number of seventh - graders. So $P=\frac{17}{23}$.

Answer:

$\frac{17}{23}$