Question

help!

Answer 1

@jim_thompson5910 how about this question..?

Answer 2

In your experience, have you seen hot chocolate served on a warm/hot summer day?

Answer 3

nooo...

Answer 4

so the colder it is, the more hot chocolate is served. Agreed?

Answer 5

agreed

Answer 6

@jim_thompson5910

Answer 7

and as the temperature outside goes up, the number of hot chocolate goes ____ (up? or down?)

Answer 8

down... @jim_thompson5910

Answer 9

yes, as one goes up, the other goes down

Answer 10

this is called an inverse relationship

Answer 11

think of a see-saw. One side goes down and pushes the other side up (or vice versa)

Answer 12

ok...

Answer 13

so whats the answer of part A?

Answer 14

Just to describe what kind of trend you see happening

Answer 15

Like with many other problems we've done together, you're just going to paraphrase what I've already explained above.

Answer 16

ok..

Answer 17

well how would you answer this?
describe the relationship between the temperature of the city and the number of cups of hot chocolate sold.

Answer 18

Give it a shot. I'll critique and help fix anything that needs fixing.

Answer 19

but i have no clue :(

Answer 20

Yes you do. We talked about it above. As the temperature outside goes up, the amount of hot chocolate gets sold goes down. As the temperature outside goes down, the amount of hot chocolate gets sold goes up. There's this \(\Large \text{inverse relationship}\) going on. One variable goes up causes another to go down and vice versa.

You're probably overthinking things.

Answer 21

oohhhhhh!!!!

Answer 22

and part b?

Answer 23

You can even throw in personal experiences of what you have seen in your life

eg: "it's winter time and it's snowing. I saw many people bundled up in line waiting to buy hot chocolate at the local cafe"

eg: "it's very hot out during the summer. Barely anyone is buying hot chocolate. Who would?"

I don't know. Something like that

Answer 24

Part B: Pick 2 points and draw a line through them. Use the slope formula to find the slope of the line through them. Make sure you do NOT pick the outlier

What two points would you pick?

Answer 25

um, 20 and 40?

Answer 26

@jim_thompson5910

Answer 27

state the x and y coordinates

Answer 28

how do i figure out the x and y coordinates? im having trouble learning this

Answer 29

this is new to me

Answer 30

@jim_thompson5910

Answer 31

pick a point you want. Move straight down til you reach the x axis. What number do you land on?

Answer 32

20

Answer 33

ok go back to that same point you picked. Now go to the left til you hit the y axis. What number do you land on?

Answer 34

20

Answer 35

so the x coordinate is 20 and the y coordinate is 20
the point is (20,20

whenever you write down a point's location, you write the pair of coordinates

Answer 36

sorry I meant to say (20,20)

Answer 37

oh ok...

Answer 38

now pick another point and repeat those same steps. Report the coordinates to me

Answer 39

you can think of it as a game of battleship. However, instead of letters, you use numbers

Answer 40

(40,40)

Answer 41

(40,40) is not a point shown

Answer 42

y doesn't even go that high

Answer 43

ok sorry let me try again

Answer 44

(40,2)

Answer 45

very good, but that is the outlier. Notice how it's all by its lonesome

Answer 46

we're going to ignore the outlier and focus on the main group non-outlier points

Answer 47

what's another point?

Answer 48

(30,18)

Answer 49

good

Answer 50

so (20,20) and (30,18) are two points shown in orange

Answer 51

find the slope of the line through them

Answer 52

how do i find that?

Answer 53

look through your notes. Remember we worked on slope earlier

Answer 54

the one where you identify the coordinates, subtract then divide

Answer 55

oh ok!

Answer 56

slope comes up a lot, so be sure to practice practice practice

Answer 57

y: 20 and 18
x: 20 and 20
2 and 0
2

Answer 58

x is not 20 and 20
one is 20 and the other is 30

Answer 59

oh whooopsies... let me try again

y: 20 and 18
x: 20 and 30
2 and -10
2/10

Answer 60

2 divided by -10 is -2/10 which reduces to -1/5

Answer 61

-1/5 is the slope of the line through the two points
m = -1/5

Answer 62

use (x,y) = (20,20) and m = -1/5 to find the value of b


y = m*x + b
20 = (-1/5)*20 + b
...
...
b = ???

Answer 63

b=24

Answer 64

good

Answer 65

m = -1/5
b = 24

the equation of the line through those two points you picked, (20,20) and (30,18), is this

y = (-1/5)x + 24

Answer 66

x=120-5y

Answer 67

you can write the regression equation as `y = (-1/5)x + 24` or as `y = -0.2x + 24`

since -1/5 = -0.2

Answer 68

y = -0.2x + 24 might be better since fractions are a pain sometimes

Answer 69

oh ok.

Answer 70

im having trouble solving it... please help me

Answer 71

what do you mean?

Answer 72

i need help solving it

Answer 73

part B? we just did

Answer 74

wait, really.. but dont i have to solve?
y = -0.2x + 24

Answer 75

what exactly do you mean by "solve"? Do you mean isolate x?

Answer 76

well is that it for part b? or do we still have more to do?

Answer 77

it's pretty much done. You just have to explain the steps

Answer 78

ok well can you give me an overview of part b please..

Answer 79

basic outline

step 1) pick two points that aren't outliers
step 2) find the slope of the line through those points
step 3) find the y intercept based on the result from step 2 and use y = mx+b. Use the coordinates from the points for x and y.

Answer 80

ok so for step 1:
The two points i picked are: (20,20) and (30,18)

?

Answer 81

@jim_thompson5910

Answer 82

yes, so far so good

Answer 83

ok and for step 2, i do the subtract and divide thing?

Answer 84

yes

Answer 85

ok so how can i explain those steps?

Answer 86

you can use words or use symbols

Answer 87

however you find it more natural

Answer 88

i know but how do i say it? like..
step 2:
now we have to find the slope of each pair.
x: 20 and 30
y: 20 and 18
Now we subtract each.
20-30= -10
20-18=2
Now we divide.
-10/2

Answer 89

you can say "subtract each corresponding coordinate"

Answer 90

and you are dividing in the wrong order

Answer 91

y goes first?

Answer 92

yes y up top

Answer 93

ok...

Answer 94

slope = `change in y` over `change in x`

Answer 95

step 2:
now we have to find the slope of each pair.
y: 20 and 18
x: 20 and 30
Now we subtract each corresponding coordinate.
20-18=2
20-30= -10
Now we divide.
2/-10 = -1/5

Answer 96

good

Answer 97

actually, one little change to make

change "slope of each pair" to "slope of the line"