Draw a line that fits the dots

Answer Key - Grade 8 Math Worksheet - Challenge Me

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

1. 1.

   Ren drew a fit line through six dots on the guitar club's plot. How good is it? What is the total of the up-or-down distances from all six dots to the line?

   14
2. 2.

   Tala rolled a toy car down a ramp at six heights and drew a fit line. What is the total of the up-or-down distances from all six dots to the line?

   28
3. 3.

   Ari plotted six classmates' spelling practice against words spelled right and drew a fit line. What is the total of the up-or-down distances from the dots to the line?

   14
4. 4.

   Bo plotted bus riders' distance to school against their ride times. One rider's bus stopped for a parade. Which ruler line is the best fit, and why?

   • Line B, because it is pulled toward every dot, even (8, 58), the dot far from the rest.
   • Line C, because it joins the first and last dots.
   • Line A, because it stays close to every dot except the outlier (8, 58).
5. 5.

   Esme measured nine park trees: trunk width and height. One tree is a very tall pine. Which ruler line is the best fit, and why?

   • Line A, because it is pulled toward every dot, even (30, 30).
   • Line C, because it stays close to every dot except the outlier (30, 30).
   • Line B, because it joins the first and last dots.
6. 6.

   Jun's play-ball club plotted practice rolls against how many of 20 rolls hit a target. One player had an amazing lucky day. Which ruler line is the best fit, and why?

   • Line A, because it joins the first and last dots.
   • Line C, because it is pulled toward every dot, even (30, 18).
   • Line B, because it stays close to every dot except the outlier (30, 18).
7. 7.

   Kira timed nine loaves of bread rising. One loaf got a double scoop of yeast by mistake. Which ruler line is the best fit, and why?

   • Line A, because it stays close to every dot except the outlier (90, 30.5).
   • Line C, because it is pulled toward every dot, even (90, 30.5).
   • Line B, because it joins the first and last dots.
8. 8.

   Luz logged nine bike rides by time and distance. Is a straight fit line a good model for these dots? Which answer gives a good reason?

   • No, because 9 dots are too few to show a pattern.
   • No, because the dots follow a curve that bends.
   • No, because the dots do not all sit exactly on one line.
   • Yes, because the dots stay near one straight line.
9. 9.

   Pia's puppy got weighed nine times as it grew. It wiggled every time. Is a straight fit line a good model? Which answer gives a good reason?

   • No, because the dots show no pattern.
   • No, because the dots follow a curve that bends.
   • Yes, because a ruler line can go through the middle of any dots.
   • Yes, because the dots change steadily from left to right.
10. 10.

    Ren timed nine runners and noted their shoe sizes. Is a straight fit line a good model for these dots? Which answer gives a good reason?

    • No, because the dots follow a curve that bends.
    • Yes, because a ruler line can go through the middle of any dots.
    • No, because the dots show no clear pattern.
    • Yes, because the first dot is lower than the last dot.