Question

Put in point slope form and slope intercept form y1=14% y2=12.5% x1=5 x2=13
I don't know how to find the slope

Answer 1

Hey Britt c:

What are the percents about? 0_o Hmm

Answer 2

A multi-year analysis was begun in 1987 to determine the percentage of American women claiming to be on a weight-loss diet.
5 years into the study, 14\% of women were found to be on a diet, while 13 years into the study, 12.5\% of women were found to be on a diet

Answer 3

Hmm ok good, so you've labeled your x's and y's correctly :)

Answer 4

Let \, y \, = percentage of women on a diet, and let \, x \, = number of years into the study

Answer 5

yes :)

Answer 6

Taking the different of the y's tell us the `vertical height` between the points.
\(\Large\rm y_2-y_1\) we often call this "rise".

Taking the difference of the x's tells us the `horizontal distance` between the points.
\(\Large\rm x_2-x_1\) we often call this "run".

Our slope is the ratio of the rise to the run.
Change in height divided by change in ... distance or whatever.


\[\Large\rm slope=\frac{y_2-y_1}{x_2-x_1}\]

So we just need to plug in those points and simplify :O

Answer 7

You're using Point-Slope form of a line? Ooo goodie, that mean you'll have a little bit less work. We need only find the slope, then plug the stuff in.

Answer 8

\[\Large\rm slope=\frac{12.5\text{%}-14\text{%}}{13-5}\]Understand how I plugged those into the formula? :O

Answer 9

yes

Answer 10

Simplify the top and bottom! c:
What do you get?

Answer 11

Oh boy :( The website is tweaking out again!

Answer 12

i got -.015/8

Answer 13

but i can't use decimals

Answer 14

You can't? :O
Oh I see.

Answer 15

What happened in your numerator?
Ohhh did you turn the % into a decimal or something?

Answer 16

\[\Large\rm slope=\frac{-1.5\text%}{8}\]and you wrote it as,\[\Large\rm slope=\frac{-.015}{8}\]Umm I guess to get rid of the decimal, we'll have to multiply by a bunch of 10's.
Multiplying by 10 moves the decimal one place.
Multiplying by two tens (which is the same as multiplying by 100) will move it two places.

So we'll need to multiply our expression, top and bottom, by 1000, to move the decimal three places.\[\Large\rm slope=\frac{-.015}{8}\left(\frac{1000}{1000}\right)\]

Answer 17

\[\Large\rm slope=-\frac{150}{8000}\]

Answer 18

This number doesn't make a whole lot of sense though D:
It's telling us that 150 less people will be on this diet every 8000 years.
-_-

Can't we just leave it in percent form or no? :o

Answer 19

umm let me see

Answer 20

i'm not sure. this is the problem attached

Answer 21

MSU? :D
Oooo neato

Answer 22

Did you misread the question maybe silly? :D
I see a line that says "Decimals `are` allowed throughout this problem".

Answer 23

oh whoops, i just assumed because all the other ones it said no decimals okay hold on ha

Answer 24

ah :)

Answer 25

is it -.015/8(x-.125)?

Answer 26

Woops your `x` isn't plugged in correctly.
You plugged your y2 into it.

Answer 27

I would simplify your slope a little bit further.
If you want to leave it as an ugly fraction like that it's fine....

But if you just toss it into the calculator it gives you: slope=-0.1875
ya?

Answer 28

-0.1875(x-5) plugged it in and its correct :)

Answer 29

yay team \c:/

Answer 30

hmm but i tried to put it in slope intercept form and got .1875x+14.94 and it says its wrong

Answer 31

Hmm slope intercept form is a little tricky D:
We can get there from point-slope form though.

Answer 32

\[\Large\rm y-14=-.1875(x-5)\]Distributing the -.1875 gives us,\[\Large\rm y-14=-.1875x+0.9375\]Adding 14,\[\Large\rm y=-.1875x+14.9375\]WHUT? It looks like you did it correctly.
Wrong answer? D:
Is the rounding the problem maybe?