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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?

 Jan 17, 2020

Best Answer 

 #1
avatar+122 
+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

 Jan 17, 2020
edited by danne9000  Jan 17, 2020
 #1
avatar+122 
+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
edited by danne9000  Jan 17, 2020
 #2
avatar+107405 
+2

Nice work, danne9000  !!!

 

 

 

cool cool cool

CPhill  Jan 17, 2020

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