## jayda 2 years ago The scatter plot below shows the weights in ounces of several kittens at various ages. What is the best equation of the trend line through these points? A. y = 10x B. y = 4x C. y = 1/4x + 10 y = 4x + 10

1. jayda

2. mathmate

This is how you proceed for slope-intercept equations. From the graph, read off the y-intercept (=10). Read off the slope (about 15). Check the 4 options to see which one satisfies both conditions. If you can use help reading off the slope and intercept, please post.

3. jayda

what do you mean

4. mathmate

Are you familiar with how to find the y-intercept of a given equation in slope-intercept form?

5. jayda

not really

6. mathmate

An equation y=mx+b is in slope-intercept form, where m=slope and b=y-intercept. |dw:1357747417191:dw|

7. mathmate

@jayda ok so far?

8. jayda

yes

9. mathmate

From the given graph, can you spot the y-intercept?

10. jayda

would it be 1?

11. mathmate

no. Y-intercept is where the curve (line in this case) intersects the y-axis. Can you read it off?

12. jayda

so the y intercept is where you have the curved line?

13. mathmate

|dw:1357748329385:dw| Can you figure out the y-intercept of the given graph?

14. jayda

ohh . okay . yes

15. mathmate

can you do the rest now?

16. mathmate

What is the approximate slope and what is the intercept?

17. jayda

isnt the intercept 10 though?

18. jayda

@mathmate ?

19. mathmate

Right, y-intercept is 10. Did you find the slope?

20. jayda

would it be 4?

21. jayda

22. mathmate

Your answer D is correct. You have eliminated A and B because the y-intercepts there are zero. Good job. Between C and D, the difference is the slope. The graph shows that y increases from 10 to 14 between 0 and 1. This implies a slope of (14-10)/(1-0)=4. Therefore answer D is correct.

23. jayda

thank you so much ! (:

24. mathmate

yw! :)