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Grade 8 · Math

8th grade Random samples from a known group worksheet

6 printable versionsBuilding Confidence10 questions · answer keyFree · no account

Level: Building Confidence · On Level · Challenge Me

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Random samples from a known group

Grade 8 Math Worksheet - Building Confidence

NameDate

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

  1. Each sample is drawn without looking; return all counters before the next. Bo has a bag with 3 blue counters out of 10. Bo draws 4 random samples of 5, returning all counters each time. About how many blue draws would match the bag's makeup?

  2. 4 blue dots and 6 yellow dots. Each sample is drawn without looking; return all counters before the next. Esme has a bag with 4 blue counters out of 10. Esme draws 5 random samples of 6, returning all counters each time. About how many blue draws would match the bag's makeup?

  3. Luz has a bag with 8 blue counters out of 10. Luz draws 4 random samples of 5, returning all counters each time. About how many blue draws would match the bag's makeup?

  4. 7 blue dots and 5 yellow dots. Each sample is drawn without looking; return all counters before the next. Milo has a bag with 7 blue counters out of 12. Milo draws 4 random samples of 6, returning all counters each time. About how many blue draws would match the bag's makeup?

  5. Each sample is drawn without looking; return all counters before the next. Noah has a bag with 3 blue counters out of 10. Noah draws 6 random samples of 5, returning all counters each time. About how many blue draws would match the bag's makeup?

  6. 4 blue dots and 6 yellow dots. Each sample is drawn without looking; return all counters before the next. Pia has a bag with 4 blue counters out of 10. Pia draws 6 random samples of 5, returning all counters each time. About how many blue draws would match the bag's makeup?

  7. 7 blue dots and 3 yellow dots. Each sample is drawn without looking; return all counters before the next. Tala has a bag with 7 blue counters out of 10. Tala draws 6 random samples of 5, returning all counters each time. About how many blue draws would match the bag's makeup?

  8. Zee has a bag with 8 blue counters out of 10. Zee draws 6 random samples of 5, returning all counters each time. About how many blue draws would match the bag's makeup?

  9. Read this first

    Population dot plot

    5 blue, 5 yellow. Four five-dot sample plots have blue counts 2, 3, 1, 3. Draw without looking and return all counters between samples.

  10. Ari draws four random samples of five counters from a known bag with 5 blue of 10. Which statement best describes how the samples represent the bag?

    • Different blue counts prove the drawing method was unfair.
    • Only the first sample tells us the bag’s blue share.
    • The samples differ, but their combined blue share is near the bag’s blue share.
    • Equal-size random samples must have the same blue count, as they come from one bag.
  11. Jun draws four random samples of five counters from a known bag with 7 blue of 10. Which statement best describes how the samples represent the bag?

    • Different blue counts prove the drawing method was unfair.
    • The samples differ, but their combined blue share is near the bag’s blue share.
    • Only the first sample tells us the bag’s blue share.
    • Equal-size random samples must have the same blue count.
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8th grade Random samples from a known group worksheet – printable
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About this worksheet

Random samples that represent a group. Every version has 10 questions, and the answer key prints on the second page.

What your child will learn

  • I can use the known bag's dots to predict about how many blue draws a run would have.
  • I can combine several equal-size samples and find the share that was blue.
  • I can explain why random samples differ while their combined share can be near the bag’s share.
  • I can judge a sample by how it was drawn: without looking or picked by hand.
  • I can compare two runs with the known bag and estimate a bag from combined samples.

Standard: state-only (CCSS 7.SP.A.1–2)

Words to know

population: The whole bag of counters; every counter is one dot.

random sample: Counters drawn without looking, so each counter has a fair chance.

run: Several samples drawn in the same way.

expected count: About how many blue draws match the bag's blue share over a whole run.

combined share: Blue dots in all samples divided by all sampled dots.

Common mistakes

Your child counted the other color. Ask which dot stack the question names.

Your child assumed half the dots are blue. Compare the blue stack with all the dots.

Your child treated the bag's blue count as the blue count in every smaller sample. Scale each sample first.

Questions parents ask

What is the most common mistake with random samples from a known group?

Your child counted the other color. Ask which dot stack the question names.

Are these 8th grade math worksheets free to print?

Yes. All 6 printable versions at each level are free to print, with the answer key, and no account is needed.

More grade 8 math

See all grade 8 math

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