suppose you have to survey 70 students in a school. there are 230 grade 9s, 215 grade 10s, 195 grade 11, 190 grade 12s, how many students should you survey from each grade so that the numbers are proportional to the number of students in each grade?

Guest Jan 17, 2020

#1**+2 **

Find total

230+215+195+190= 830 students.

Next you divide the numbers from each grade with the total for the school to find the proportions for each grade.

I.e.

Grade 9 = 230/830=0.277

Grade 10=215/830=0.259

Grade 11=195/830= 0.235

Grade 12=190/830=0.229

The just multiply each result with the number you're surveying (70*0.277= 19.39 to survey from grade 9).

Then you end up with;

19 from grade 9

18 from grade 10

17 from grade 11

16 from grade 12

danne9000 Jan 17, 2020

#1**+2 **

Best Answer

Find total

230+215+195+190= 830 students.

Next you divide the numbers from each grade with the total for the school to find the proportions for each grade.

I.e.

Grade 9 = 230/830=0.277

Grade 10=215/830=0.259

Grade 11=195/830= 0.235

Grade 12=190/830=0.229

The just multiply each result with the number you're surveying (70*0.277= 19.39 to survey from grade 9).

Then you end up with;

19 from grade 9

18 from grade 10

17 from grade 11

16 from grade 12

danne9000 Jan 17, 2020