Ethan recorded the grade-level and instrument of everyone in the middle school School of Rock below.
Seventh Grade Students
Instrument # of Students
Guitar 10
Bass 4
Drums 14
Keyboard 14
Eighth Grade Students
Instrument # of Students
Guitar 6
Bass 6
Drums 15
Keyboard 10
Based on these results, express the probability that a seventh grader chosen at random will play an instrument other than bass as a percent to the nearest whole number.
Answer
Attempt 1 out of 3
In total, there are 42 seventh grade students in the School of Rock. The number of seventh graders who play an instrument other than bass is 10 (guitar) + 14 (drums) + 14 (keyboard) = 38.
The probability that a seventh grader chosen at random will play an instrument other than bass is 38/42 = 0.9048.
Converting this to a percent to the nearest whole number, the probability is 90%.