The total number of eighth-grade students is:
10 + 3 + 12 + 12 = 37
The number of eighth-grade students who play an instrument other than guitar is:
3 + 12 + 12 = 27
Therefore, the probability that an eighth-grader chosen at random will play an instrument other than guitar is:
27/37 ≈ 0.73
To express this as a percentage to the nearest whole number, we multiply by 100 and round to the nearest whole number:
0.73 × 100 ≈ 73
Therefore, the probability is approximately 73%.