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.

   Kira timed eight bike rides of different lengths and plotted them. A ruler line is drawn through the middle of the dots. Which sentence describes the association?

   • No association: as the ride length goes up, the ride time tends neither to go up nor to go down.
   • A positive association: as the ride length goes up, the ride time tends to go up.
   • A negative association: as the ride length goes up, the ride time tends to go down.
2. 2.

   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 positive association: as the outside temperature goes up, the number of cups poured tends to go up.
   • No association: as the outside temperature goes up, the number of cups poured tends neither to go up nor to go down.
   • A negative association: as the outside temperature goes up, the number of cups poured tends to go down.
3. 3.

   On a class trip up a mountain road, Milo read the temperature at each stop. A ruler line is drawn through the middle of the dots. Which sentence describes the association?

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

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

   • No association: as the shoe length goes up, the height tends neither to go up nor to go down.
   • 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.
5. 5.

   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.
   • A negative association: as the practice time goes up, the amount of water left tends to go down.
   • No association: as the practice time goes up, the amount of water left tends neither to go up nor to go down.
6. 6.

   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 positive association: as the dog's weight goes up, the number of tricks tends to go up.
   • A negative association: as the dog's weight goes up, the number of tricks tends to go down.
7. 7.

   Ari logged reading time and pages read for eight days. On one day, a chatty parrot sat by the library window. Which point is the outlier, written as (x, y)?

   (35, 12)
8. 8.

   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)
9. 9.

   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)
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