Question

The scatter plot shows different students’ grade point averages (GPA) and scores on a test.

What is the equation of the graphed linear model?

y = x +
http://static.k12.com/calms_media/media/1549000_1549500/1549112/4/7390c9fb9a63b8e12222a8022220158e8dc6e5ae/MS_IMC-141014-181216.jpg

Answer 1

@Mehek14

Answer 2

I only have this and one more please

Answer 3

@perl

Answer 4

Do you know how to find slope?

Answer 5

I kinda do

Answer 6

Its rise over run. So find where the line goes through a point on the graph... I'll try to edit the pic so i can show u what i mean. One min

Answer 7

ok

Answer 8

Okay so first, find 2 points that are easily labeled.

Answer 9

You can pick any of the 2.

Answer 10

ok

Answer 11

So one would be (0,40) what would another one be?

Answer 12

first and last points

Answer 13

You can choose any of the red dots because they fall on the graph's lines. It just makes it easier to find what the coordinate is.

Answer 14

So your other one you choose could be (1,55). Correct?

Answer 15

(4.0,100)?

Answer 16

Yes!

Answer 17

or that

Answer 18

So now the formula to find the slope is: rise over run or \[\frac{ rise }{ run }\]

Answer 19

Do you know how to find rise ?

Answer 20

no slope aint really mah strong stuff

Answer 21

sorry

Answer 22

lol it's ok. Rise is basically what it says, rise like how much you move up (or down). What axis would that be?

Answer 23

the x-axis or the y-axis?

Answer 24

x?

Answer 25

no the x-axis numbers go across, the y goes up and down.

Answer 26

oh I thought You mean diagnally

Answer 27

So to find the rise, take your 2 points which we decided would be (0,40) and (4,100) right?

Answer 28

ohh no sorry i mean like straight up

Answer 29

yes

Answer 30

I understood

Answer 31

So to find the rise(how much it goes straight up or down) take the Y coordinate of each point and subtract them. So then it would be 100-40. Do u get that part?

Answer 32

brb one sec

Answer 33

kk

Answer 34

But you could also do 40-100, just make sure when u do the run part you subtract those in the same way you did the rise.

Answer 35

back

Answer 36

-60?

Answer 37

@Thatonegirl_

Answer 38

Yup. Now that is your rise. To find the run, take the x coordinates of each of the points and subtract them. (if for the rise you subtracted the y coordinate from the first point then the second one, do it the same for the x)

Answer 39

You did 40-100=-60. So you can't now do 4-0 because your taking them from the wrong ones. Does that make sense?? You just need to follow the same pattern when subtracting.

Answer 40

To tell the truth I'm very confused

Answer 41

\[\frac{ y_2-y_1 }{ x_2-x_1 } \]

Answer 42

Okay sorry I'm really bad at explaining things... That is the formal equation for the slope. Y2 is just the y from the second point. Y1 is the y from the first point. X2 is the x from the second point, and x1 is from the first.

Answer 43

(0,40),(4,100)
\[\frac{ 100-40 }{ 4-0}\]

Answer 44

60
4?

Answer 45

Yep!! \[\frac{ 60 }{ 4 }=15\]

Answer 46

so what the y=___x+____

Answer 47

So your slope is just 15. If the numbers were weird and didn't divide nicely you would just keep it in the fraction form. But 15 is nice (just keep in mind it is actually 15/1)

Answer 48

That is ur slope so you get y=15x+___

Answer 49

y=mx+b. M=slope b=y-intercept, where it crosses the y-axis.

Answer 50

If you look at the graph, it crosses the y axis at 40 but just to make sure you can always plug in any point into the equation. So let's say you pick (2,70)
70=15(2)+b
70=30+b
40=b

Answer 51

so y=15x+40?

Answer 52

yep!

Answer 53

omg ty thanks

Answer 54

Do you have any other problems you want to practice and I can help if you get stuck since this was pretty rough xD??

Answer 55

Yeah anytime :D

Answer 56

XD

Answer 57

Ty no I'll see you next time it's really late

Answer 58

Okay hope this sorta helped :S

Answer 59

XD

Answer 60

:P lol