Use the fit line's equation to predict, and say what its slope and intercept mean

Answer Key - Grade 8 Math Worksheet - Challenge Me

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

1. 1.

   Kira's class model is y = 4x + 30 for hours of practice a week (x) and quiz score (y). About how many hours of practice go with a score of 70?

   10
2. 2.

   Luz's bean plant model is y = 2.5x + 5, with x in days and y in cm. About how many days after planting does a plant reach 25 cm?

   8
3. 3.

   Noah's sunflower model is y = 1.5x + 12 for days since planting (x) and height in cm (y). About how many days after planting does a sunflower reach 33 cm?

   14
4. 4.

   Pia's piano club drew a fit line through (2, 18) and (8, 36). What is the line's equation, written like y = 2x + 5?

   y = 3x + 12
5. 5.

   Ren's sunflower fit line passes through (4, 20) and (10, 35). What is the line's equation, written like y = 2x + 5?

   y = 2.5x + 10
6. 6.

   Tala's reading club drew a fit line through (5, 30) and (15, 50). What is the line's equation, written like y = 2x + 5?

   y = 2x + 20
7. 7.

   Zee drew a fit line through (10, 24) and (30, 40) on a plot of walks. What is the line's equation, written like y = 2x + 5?

   y = 0.8x + 16
8. 8.

   Ari's class model is y = 4x + 30 for hours of practice (x) and quiz score (y). With 5 more hours, about how many more points does it predict?

   20
9. 9.

   Bo's seedling model is y = 1.5x + 4, with x in days and y in cm. Over 10 more days, about how many centimeters taller does it predict a seedling grows?

   15
10. 10.

    Esme's bike model is y = 3x + 5 for km (x) and minutes (y). A new route is 4 km longer. About how many more minutes does the model predict?

    12