Scatter plots: patterns of association

Answer Key - Grade 8 Math Worksheet

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

1. Read this first

   Table, quiz score | minutes studied

   72 | 20, 80 | 35, 88 | 45, 91 | 60. On the scatter plot, the minutes studied go across (x) and the quiz scores go up (y).

2. 1.

   Luz's table lists each student's quiz score first, then the minutes studied. Where does the dot for the student who studied 45 minutes go, written as (x, y)?

   (45, 88)

3. Table, height in centimeters | days since planting

   18 | 10, 45 | 20, 80 | 30, 120 | 40. On the scatter plot, the days since planting go across (x) and the heights go up (y).

4. 2.

   Milo wrote a sunflower's height first, then the days since planting, in each row of a table. Where does the dot for day 30 go, written as (x, y)?

   (30, 80)
5. 3.

   Esme plotted how many pages each book has and how many days it took to finish. One book was about a lost penguin. Which sentence describes the association?

   • A negative association: as the number of pages goes up, the number of days tends to go down.
   • A positive association: as the number of pages goes up, the number of days tends to go up.
   • No association: as the number of pages goes up, the number of days tends neither to go up nor to go down.
6. 4.

   Kira recorded the heights of eight classmates and their spelling scores. Which sentence describes the association?

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

   On eight days, Bo noted the noon temperature and the number of books checked out from the class library. Which sentence describes the association?

   • No association: as the noon temperature goes up, the number of books checked out tends neither to go up nor to go down.
   • A negative association: as the noon temperature goes up, the number of books checked out tends to go down.
   • A positive association: as the noon temperature goes up, the number of books checked out tends to go up.
8. 6.

   On a long field trip, Ren checked the miles driven and the gas left in the bus at each stop. Which sentence describes the pattern of the dots?

   • No association: the dots tend to show no clear pattern.
   • A linear association: the dots tend to stay near one straight ruler line.
   • A nonlinear association: the dots tend to follow a curve, not one straight line.
9. 7.

   Tala plotted hours of practice a week against free throws made for eight players. Which point is the outlier, written as (x, y)?

   (2, 13)
10. 8.

    After the lunch bell, Ari counted the kids still on the playground each minute. At one count, another class came out early. Which point is the outlier, written as (x, y)?

    (6, 47)
11. 9.

    Milo's baking club recorded the grams of flour and the number of cookies in each batch. One batch was giant cookies. Which point is the outlier, written as (x, y)?

    (300, 7)
12. 10.

    Zee measured the stems and flower widths of tulips and sunflowers in the school garden. How many flowers are in the cluster of taller flowers?

    5