There are 80 girls and 70 boys in the 6th Grade at a middle school. Of these students 12 girls and 9 boys write left handed. What percentage of the sixth graders at this middle school write left-handed

About 7% of the students

In order to do this problem, we first need to find the total number of sixth graders at that middle school. When we add the boys to the girls (80+70), we find that number to be 150 (because 80+70=150). Now that we know the total, we can find out how many of them write left-handed. To do this, we just have to add the number of boys and girls that write left-handed (12+9). When we do this, we find that 21 of them write left-handed (because 12+9=21). Now that we know the total number of left-handed students, we need to find the percentage this is out of all the students. To do this, we divide 21 by 150 and we get about 7.14 which, when rounded down, means about 7 percent of students at this particular middle school write left-handed.

So, your answer is about 7 percent.