Predict about a whole group from a sample

Answer Key - Grade 7 Math Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.

1. 1.

   Esme took four random samples of 20 students each from 400 students. The crust had no comment. Using all four samples together, about how many of the 400 students choose pizza for lunch?

   150
2. 2.

   Noah took four random samples of 25 students each from 500 students. One sneaker squeaked. Using all four samples together, about how many of the 500 students walk to school?

   210
3. 3.

   Ari took four random samples of 15 students each from 360 students. Nobody read the survey upside down. Using all four samples together, about how many of the 360 students read a book yesterday?

   132
4. 4.

   Tala took four random samples of 20 students each from 280 students. The bin stayed neat. Scale the lowest and highest samples up to all 280. How far apart are the two predictions?

   56
5. 5.

   Jun took four random samples of 30 students each from 420 students. One kazoo was mentioned. Scale the lowest and highest samples up to all 420. How far apart are the two predictions?

   56

6. Read this first

   Use this

   Four random samples of 20 students each, taken from 360 students, were asked "Do you ride the bus?" Sample A: 8 yes, 12 no; Sample B: 12 yes, 8 no; Sample C: 9 yes, 11 no; Sample D: 10 yes, 10 no.

7. 6.

   Pia took four random samples of 20 students each from 360 students. The bus stayed on time. Scale the lowest and highest samples up to all 360. How far apart are the two predictions?

   72

8. Use this

   Four random samples of 20 students each, taken from 540 students, were asked "Do you bring a lunch from home?" Sample A: 6 yes, 14 no; Sample B: 11 yes, 9 no; Sample C: 8 yes, 12 no; Sample D: 9 yes, 11 no.

9. 7.

   Bo took four random samples of 20 students each from 540 students. A sandwich was well packed. Scale the lowest and highest samples up to all 540. How far apart are the two predictions?

   135
10. 8.

    Milo took four random samples of 20 students each from 400 students. Several tails wagged. Which conclusion about all 400 students do the samples support?

    • The samples suggest between 5 and 9 of the 400 students have a pet dog, using the counts in the samples; it is only a guess, not proof.
    • The samples suggest about 100 of the 400 students have a pet dog; it is only a guess, not proof.
    • The samples suggest exactly 140 of the 400 students have a pet dog; it is only a guess, not proof.
    • The samples suggest between 100 and 180 of the 400 students have a pet dog; it is only a guess, not proof.
11. 9.

    Zee took four random samples of 20 students each from 320 students. A bell rang twice. Which conclusion about all 320 students do the samples support?

    • The samples suggest about 112 of the 320 students own a bike; it is only a guess, not proof.
    • The samples suggest between 7 and 11 of the 320 students own a bike, using the counts in the samples; it is only a guess, not proof.
    • The samples suggest exactly 144 of the 320 students own a bike; it is only a guess, not proof.
    • The samples suggest between 112 and 176 of the 320 students own a bike; it is only a guess, not proof.
12. 10.

    Four random samples of 15 students each, taken from 360 students, were asked "Do you like the new playground?" Ren took four random samples of 15 students each from 360 students. The swings kept swinging. Which conclusion about all 360 students do the samples support?

    • The samples suggest about 120 of the 360 students like the new playground; it is only a guess, not proof.
    • The samples suggest between 5 and 8 of the 360 students like the new playground; it is only a guess, not proof.
    • The samples suggest exactly 150 of the 360 students like the new playground; it is only a guess, not proof.
    • The samples suggest between 120 and 192 of the 360 students like the new playground; it is only a guess, not proof.