Does this sample fairly show the whole group?

Answer Key - Grade 7 Math Worksheet - Building Confidence

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

1. 1.

   Ari wants to learn about every tomato plant in the school bed but measures only 3 of them. One tomato plant leaned toward the camera. Which choice names the population, the whole group?

   • the heights in inches
   • all 9 tomato plants in the school bed
   • all the tomato plants in town
   • the 3 tomato plants Ari measured
2. 2.

   Luz wants to learn about every member of the piano club but measures only 3 of them. The piano was not available for comment. Which choice names the population, the whole group?

   • the minutes of practice a week
   • the 3 piano club members Luz measured
   • all the piano clubs in the county
   • all 8 members of the piano club
3. 3.

   Tala wants to learn about every rider in the bike club but times only 4 of them. A bike bell rang at the wrong moment. Which choice names the sample, the part that was picked?

   • all the riders in the state
   • all 10 riders in the bike club
   • the 4 riders Tala timed
   • the miles ridden on Saturday
4. 4.

   Jun wants to learn about every pet snail in the science room but times only 3 of them. No snail was rushed. Which choice names the sample, the part that was picked?

   • the centimeters crawled in a minute
   • all the snails in the world
   • all 8 pet snails in the science room
   • the 3 pet snails Jun timed
5. 5.

   Picture each of the 240 students as one dot on a dot plot. The sample is the 8 dots picked. Pia wants to know how many minutes the 240 students at Maple School read each night, and can ask 8 students. Which way of choosing gives a sample that fairly shows all 240?

   • Ask the 8 students who belong to the school book club.
   • Ask the 8 students who sit closest to the classroom door.
   • Ask the first 8 students who volunteer to answer.
   • Draw 8 names from a hat holding all 240 student names.

6. Read this first

   Use this

   Picture each of the 90 bean plants as one dot on a dot plot. The sample is the 9 dots picked.

7. 6.

   Milo wants to know how tall the 90 bean plants in the school garden are, and can measure 9. Which way of choosing gives a sample that fairly shows all 90?

   • Measure the 9 plants in the sunniest row.
   • Measure the 9 plants the gardener says look best.
   • Measure the 9 plants closest to the garden path.
   • Draw 9 plant tags from a bag holding all 90 tags.
8. 7.

   Picture each of the 200 players as one dot on a dot plot. The sample is the 10 dots picked. Zee wants to know how many minutes the 200 players in a school band practice each week, and can ask 10 players. Which way of choosing gives a sample that fairly shows all 200?

   • Give every player a number and let a random-number tool pick 10.
   • Ask the 10 players who sit in the first chairs.
   • Ask the 10 players who answer Zee's note.
   • Ask the 10 players who are in the band room right now.
9. 8.

   Kira measured all 8 sunflowers, then picked the 3 tallest. One leaned toward the camera. How far is the mean of the 3 picked from the mean of all 8?

   6.5
10. 9.

    Ren measured all 8 runners, then picked the 3 fastest. Nobody tripped over a shoelace. How far is the mean of the 3 picked from the mean of all 8?

    2
11. 10.

    Noah measured all 8 leaves, then picked 4 tags from a bag of 8. A squirrel supervised. How far is the mean of the 4 picked from the mean of all 8?

    0.5