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, minutes of practice a day | songs learned in a month

   10 | 2, 20 | 3, 30 | 5, 40 | 6. On the scatter plot, the minutes of practice go across (x) and the songs learned go up (y).

2. 1.

   Bo kept a table of daily piano practice and songs learned each month. A cat napped on the keys once. Where does the dot for the 30-minute row go, written as (x, y)?

   (30, 5)

3. 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).

4. 2.

   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)
5. 3.

   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?

   • A positive association: as the ride length goes up, the ride time tends to go up.
   • No association: as the ride length goes up, the ride time tends neither to go up nor to go down.
   • A negative association: as the ride length goes up, the ride time tends to go down.
6. 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.
   • 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.
7. 5.

   Tala asked eight classmates how long their bus ride to school takes and what they scored on a quiz. Which sentence describes the association?

   • A negative association: as the bus ride time goes up, the quiz score tends to go down.
   • A positive association: as the bus ride time goes up, the quiz score tends to go up.
   • No association: as the bus ride time goes up, the quiz score tends neither to go up nor to go down.
8. 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.
9. 7.

   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)
10. 8.

    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)
11. 9.

    Noah asked classmates how many blocks they live from school and how long the trip takes. The dots form two clusters. How many dots are in the cluster of kids who live farther away?

    7
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