The answer to the first problem is G.
Since there are 3 boys and 9 girls who are left-handed, that makes 12 people in total in sixth grade who are left-handed. The total number of sixth graders at the middle school is 150 since there are 90 girls and 60 boys in that grade. Divide 150 from 12 to get 0.08. You change it to percentage form by multiplying 0.08 by 100 to get 8%.
The answer for the second problem is C. You change the percentage (in this case it is 76%) to decimal form by dividing by 100 to get 0.76. You then multiply 0.76 with 8,950 to get 6,802.