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. Read this first

   Table, days since planting | height in centimeters

   4 | 3, 8 | 7, 12 | 10, 16 | 14. On the scatter plot, the days since planting go across (x) and the heights go up (y).

2. 1.

   Esme measured a bean plant every few days and filled in a table. The plant now has its own name tag. Where does the dot for day 12 go, written as (x, y)?

   (12, 10)

3. Table, wind speed in mph | kite height in meters

   5 | 12, 8 | 20, 11 | 26, 14 | 35. On the scatter plot, the wind speeds go across (x) and the kite heights go up (y).

4. 2.

   Jun flew a kite on four windy days and made a table. One day the kite tried to visit a cloud. Where does the dot for the 11 mph day go, written as (x, y)?

   (11, 26)
5. 3.

   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.
   • 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.
6. 4.

   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.
   • A positive association: as the height goes up, the temperature tends to go up.
   • No association: as the height goes up, the temperature tends neither to go up nor to go down.
7. 5.

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

   • 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.
   • A negative association: as the shoe length goes up, the height tends to go down.
8. 6.

   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)
9. 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)
10. 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)
11. 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
12. 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