Scatter plots: patterns of association

Answer Key - Grade 8 Math Worksheet - Building Confidence

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

1. 1.

   Each evening at the outdoor ice rink, Luz noted the temperature and the cups of cocoa poured. A ruler line is drawn through the middle of the dots. Which sentence describes the association?

   • A negative association: as the outside temperature goes up, the number of cups poured tends to go down.
   • No association: as the outside temperature goes up, the number of cups poured tends neither to go up nor to go down.
   • A positive association: as the outside temperature goes up, the number of cups poured tends to go up.
2. 2.

   Noah dropped a play ball from different heights and measured each bounce. A ruler line is drawn through the middle of the dots. Which sentence describes the association?

   • A positive association: as the drop height goes up, the bounce height tends to go up.
   • No association: as the drop height goes up, the bounce height tends neither to go up nor to go down.
   • A negative association: as the drop height goes up, the bounce height tends to go down.
3. 3.

   Pia measured the shoe length and height of eight classmates. Nobody was allowed to stand on tiptoe. Which sentence describes the association?

   • A negative association: as the shoe length goes up, the height tends to go down.
   • A positive association: as the shoe length goes up, the height tends to go up.
   • No association: as the shoe length goes up, the height tends neither to go up nor to go down.
4. 4.

   During a long practice, Ren checked the water left in a bottle every ten minutes. The bottle got lighter and lighter. Which sentence describes the association?

   • A positive association: as the practice time goes up, the amount of water left tends to go up.
   • No association: as the practice time goes up, the amount of water left tends neither to go up nor to go down.
   • A negative association: as the practice time goes up, the amount of water left tends to go down.
5. 5.

   At a dog-training class, Zee wrote down each dog's weight and how many tricks it knows. One small dog can take a bow. Which sentence describes the association?

   • No association: as the dog's weight goes up, the number of tricks tends neither to go up nor to go down.
   • A negative association: as the dog's weight goes up, the number of tricks tends to go down.
   • A positive association: as the dog's weight goes up, the number of tricks tends to go up.
6. 6.

   Bo's science group pumped a water rocket for different numbers of seconds and measured how high it flew. Which point is the outlier, written as (x, y)?

   (6, 26)
7. 7.

   At field day, Esme checked the lemonade left in the cooler every ten minutes. Near the end, a helper mixed a fresh batch. Which point is the outlier, written as (x, y)?

   (80, 29)
8. 8.

   Jun rode eight bike routes and timed each one. One route was downhill with the wind behind it. Which point is the outlier, written as (x, y)?

   (12, 28)
9. 9.

   At the dog park, Pia recorded each dog's weight and height. The dots form two clusters. How many dogs are in the cluster of big dogs?

   4
10. 10.

    Ren weighed and measured a basket of lemons and oranges. The dots form two clusters. How many fruits are in the cluster of heavier fruits?

    7